Method and implant system for sacroiliac joint fixation and fusion

ABSTRACT

An improved method of fusing the sacroiliac joint and tools for accomplishing the same is disclosed. In one embodiment, the present invention is a method that uses an intra-articular joint fusion device for connecting the sacrum and ilium that includes creating a first incision in the patient&#39;s skin proximal to the patient&#39;s sacroiliac joint, inserting a surgical channel tool into the incision from the patient&#39;s posterior, creating a void in the sacroiliac joint, inserting a fusion implant into the void, the fusion implant having at least one fixation element for engagement with bone tissue in the articular surfaces of the sacrum and the ilium, and driving the fusion implant into the void such that the at least one fixation element engages with bone tissue in an articular surface of at least one of the sacrum and ilium, and the fusion implant fixes relative positions of the sacrum and ilium.

FIELD OF THE INVENTION

The present invention relates generally to medical devices and medicalmethods. More particularly, the present invention relates tomusculoskeletal surgical methods and associated surgical tools fortreatment of the sacroiliac joint.

DISCUSSION OF THE BACKGROUND

Lower back pain is a common ailment among the population and results inboth pain and suffering as well as loss of work time. Thus, approachesfor the treatment of back pain can both relieve suffering as well asreduce employee down time. Thus, effective treatments for lower backpain have both economic benefits as well as the benefit of alleviatingconsiderable suffering.

The sacroiliac joint is located in the lower back at the juncture of theilium, the upper bone of the pelvis, and the sacrum at the base of thespine. While the sacroiliac joint has a limited range of motion,dysfunction of the joint has been identified. The joint is supported bya range of ligaments including, for example, the sacroiliac ligament atthe base of the joint and the anterior sacroiliac ligament at the top ofthe joint.

The sacroiliac joint (SI joint) is increasingly being diagnosed as acommon pain generator. That is, SI joint degenerative disease andinstability are being diagnosed and treated more commonly. Sacroiliacpain may be caused by a disruption in the joint itself, a biomechanicalproblem like a muscle imbalance, trauma, an inflammatory condition likeankylosing spondylitis, or a degenerative problem as seen withpost-lumbar fusion adjacent segment disorder. Other contributing factorsinclude post pregnancy pain/instability, longer life span, and/or moreactive lifestyles. In addition, complex spine surgeries, such as forcorrection of sagittal plane deformity, often require iliac fixation tomaintain correction in patients with a high pelvic incidence or highrisk of lumbo-sacral hardware failure.

High energy pelvic ring injuries that involve disruption of the SI jointand/or displaced fractures of the sacrum present unique challenges tothe orthopedic traumatologist. Some sacral fractures require solidposterior stabilization, which may be difficult to achieve with typicaltreatment methods. Furthermore, vertically unstable sacral fractures/SIjoint disruptions have a relatively high incidence of neurovascularinjury and may require unique stabilization. Typically, a spinal surgeonwill be involved to perform lumbo-pelvic stabilization of these injuriesto provide vertical stability of the injury. However, there may besignificant soft tissue trauma associated with these injuries, makingextensive surgical approaches of elevated risk in terms of infection andwound complications.

Immobilization of the SI joint can result in significant relief of lowerback pain. Current techniques and instrumentation systems may requireextensive surgical exposure and dissection. Moreover, suchinstrumentation systems are typically designed for other applications,and not to connect and stabilize the lumbar spine and pelvis. As aresult, this can make the surgical times longer and more frustrating forsurgeons and surgical staff. For example, traditional posterior iliacscrews are often prominent because the posterior iliac crest isrelatively subcutaneous. Yet, this sometimes makes hardware painful forthe patient and at risk for pressure soreness following surgery.

Furthermore, the current techniques and instruments do not allow for asecure and consistent fusion construct. They may provide one or theother many times, but not both issues. This may lead to further SI jointinstability and a failed surgery.

It is therefore desirable to provide new surgical methods and tools fortreating damaged sacroiliac joints that securely and consistently fusethe joint.

SUMMARY OF THE INVENTION

The present invention is an improved methods and devices for theimmobilization or fusion of the Sacroiliac joint and apparatuses forfacilitating the procedure. Immobilization may refer to mechanicalholding or surgical fusion.

The present invention provides a system and surgical tools forintroducing fusion implants that may perform the functions of mechanicalfixation and stability, compression, and bony fusion. The presentinvention also relates to improved implant devices that may perform thefunctions of mechanical fixation and stability, compression, and bonyfusion. The present invention also relates to methods of introducingfusion implants into a targeted joint through a novel exposure device.Specifically, with respect to some embodiments, an approach is describedto address the SI joint through a posterior access approach whiledelivering fusion device that includes both a cavity or channel forgraft or fusion-promoting material and fixation elements which can be inthe form of helical anchors, claw or fluke anchors, blades, screws,and/or other fixation elements, which provide for compression across thesacroiliac joint. In some embodiments, a double barreled exposure devicemay be utilized to address the SI joint through a posterior approachwhile delivering both a fusion device to the SI joint and a separatefixation device for fixing the sacrum and ilium together, which can bein the form of a screw, or the like.

It is therefore an object of the present invention to provide animproved approach for both mechanical holding and surgical fusionthrough novel exposure devices described herein. The implants describedherein may be introduced through a posterior approach to address the SIjoint and the fusion device may perform the functions of fixation,compression, and bony fusion, providing a secure fixation element formechanical stability and a bony fusion element that allows for fusionbetween the sacrum and the ilium.

It is also an object of the present invention to provide an improved,combined approach for both mechanical holding and surgical fusion usingnovel fusion devices that may be introduced through a novel exposuredevice through a posterior approach, while delivering a separatefixation device which can be in the form of a screw, or the like.Furthermore, the fusion device is delivered to the joint, placed betweenthe sacrum and ilium, while the fixation device is delivered through theiliac wing, closest to the iliac crest, into the sacrum while notentering or going across the SI joint.

It is also an object of the present invention to provide novel fusionimplants that are capable of performing perform the functions offixation, compression, and bony fusion, allowing for stable fusion ofthe SI joint through a single posterior approach. However, such fusionimplants may be used in combination with other devices to mechanicallyfix and stabilize the joint.

In some embodiments, the present invention relates to a fusion implant,comprising an elongate body adapted for placement in an intra-articularspace between articular surfaces of a joint in general longitudinalalignment with a plane between the articular surfaces of the joint; atleast one fixation element for engagement with bone tissue in at leastone of the articular surfaces of the joint; and a cavity in the implantfor holding a fusion-promoting material.

In some embodiments, the present invention relates to a medicalinstrument kit, including a joint fusion implant having a central bodyand at least one lateral fixation element for engagement with bonetissue in articular surfaces of a joint, and a surgical tool having aworking channel for insertion into an incision (e.g., over a sacroiliacjoint) in a human or animal, the working channel having a hollow barrelhaving a shape for receiving the joint fusion implant including the atleast one lateral fixation element. The surgical tool may include atleast one tang at the distal end thereof for insertion in a jointexposed by the incision, where the tang is operable to secure maintain aposition of the working channel in the joint. In some implementations,and without limitation, the hollow barrel may have an oblongcross-sectional shape for accommodating the joint fusion implant andallowing the at least one fixation element to pass through the hollowbarrel without obstruction, where the hollow barrel has a substantiallyuniform transverse cross section having a substantially elliptical shapeand the elongate portions of the elliptical cross-section function aschannels for receiving the at least one lateral fixation element. Insome implementations, and without limitation, the hollow barrel may haveat least one lateral slot running longitudinally along the hollow barrelto allow the at least one fixation element to pass through the interiorpassage without obstruction. In some embodiments, and withoutlimitation, the surgical tool may further include a second workingchannel that is inserted into a second incision over an iliac wing ofthe human patient adjacent to the sacroiliac joint when the workingchannel is inserted into the sacroiliac joint. In some implementations,and without limitation, the working channel and the second workingchannel are connected by a connecting bar having a bend therein, and areconnected at an acute angle that allows the working channel to beengaged with a posterior side of the sacroiliac joint and the secondworking channel to be engaged with a posterior portion of the iliac wingsimultaneously. The kit may further include additional instruments toestablish the working channels in the first and second incisions, andfor introducing the fusion implant into the SI joint and a jointfixation device (e.g., a surgical screw) into the ilium and sacrumwithout traversing the SI joint, including a drill operable to be passedthrough the working channel into the incision and drilling a voidthrough the connective tissues in the SI joint, as well as drill bits;an inserter having a proximal end configured to attach to the fusionimplant, the inserter being operable to pass the fusion implant throughthe hollow barrel and into the joint; an impactor for driving the fusionimplant into the joint, wherein driving the fusion implant engages theat least one fixation element with articular surfaces in the joint;joint cutting instruments; dilators; guide wires; guide pins; guide pinassemblies; a rasp; a box chisel; a driver for inserting surgical screws(e.g., a flex-shaft driver); adjustable arms for stabilizing the workingchannels; and other tools that may be utilized in establishing incisionsand access to a joint or bone tissue.

In some embodiments, the present invention relates to a method includingcreating an incision proximal to the patient's SI joint, dilating theincision, engaging an exposure device with the incision, creating a voidin the SI joint, and inserting and securing a joint fusing device in thevoid between the ilium and sacrum.

In some embodiments, the present invention relates to a method includingcreating an incision proximal to the patient's SI joint, creating anincision over iliac wing, dilating the incisions, engaging the exposuredevice with both incisions, creating a void in the SI joint, inserting agraft into the void, drilling a hole through the ilium and the S1vertebra of the sacrum, and inserting a joint fusing device in the iliumand sacrum.

In some embodiments, the present invention relates to a method forrepairing a sacroiliac joint of a patient that includes creating a firstincision in the patient's skin proximal to the patient's sacroiliacjoint; inserting a first working channel into the first incision andspreading the sacroiliac joint with an inserted end of the first workingchannel; creating a void in the sacroiliac joint; inserting a fusionimplant into the void, the fusion implant having at least one fixationelement for engagement with bone tissue in the articular surfaces of thesacrum and the ilium in the sacroiliac joint; creating a second incisionin the patient's skin over an iliac wing of the patient adjacent to thesacroiliac joint; inserting a second working channel into the secondincision wherein a longitudinal axis of the second working channel doesnot intersect the sacroiliac joint; and inserting a joint fixationdevice into the ilium and the sacrum through the second working channel,wherein the joint fixation device does not traverse the sacroiliacjoint.

In some embodiments, the present invention relates to a method includingpreparing the patient for surgery (e.g., positioning the patient in aprone position to provide the surgeon access to the SI joint, general orlocal anesthesia, and the like), locating the SI joint and an incisionpoint for access to the SI joint (e.g., by blunt finger palpation),insertion of a pin or wire to create an incision, insertion of a dilatorover the pin and impacting the dilator to dilate the incision to a widththrough which instruments may be passed, inserting a working channel ofan exposure device over the dilator, securing the working channel inposition with fixing pins, removing the dilator, inserting a drill bitapparatus through the work channel, using the drill bit apparatus in theworking channel to displace bone in the SI joint thereby creating avoid, removing the drill bit apparatus, loading a joint fusion deviceinto the first working channel until the joint fusion device ispositioned proximal to the void in the patient's SI joint, inserting animpactor into the working channel and applying force to displace thegraft into the void in the patient's SI joint, inserting a driver intothe working channel, engaging the joint fusion device with the driver,and rotating the driver to rotate the joint fusion device such thatanchoring devices on said joint fusion device engage with bone tissue ofat least one of the sacrum and the ilium, removing all instruments, andclosing the incision.

In some embodiments, the present invention relates to a joint fixationmethod including preparing the patient for surgery (e.g., positioningthe patient in a prone position to provide the surgeon access to the SIjoint, general or local anesthesia, and the like), locating the SI jointand an incision point for access to the SI joint (e.g., by blunt fingerpalpation), insertion of a pin or wire to create an incision, insertionof a dilator over the pin and impacting the dilator to dilate theincision to a width through which instruments may be passed, inserting aworking channel of an exposure device over the dilator, securing theworking channel in position with fixing pins, removing the dilator,inserting a drill bit apparatus through the work channel, using thedrill bit apparatus in the working channel to displace bone in the SIjoint thereby creating a void, removing the drill bit apparatus,excavating cortical bone tissue from articular surfaces within thejoint, loading a joint fusion device into the first working channeluntil the joint fusion device is positioned proximal to the void in thepatient's SI joint, inserting an impactor into the working channel andapplying force to displace the joint fusion device into the void in thepatient's SI joint, removing all instruments, and closing the incision.

In some embodiments, the present invention relates to a method ofimplanting a fusion device into a sacroiliac joint of a patient,including creating an incision in the patient's skin proximal to thepatient's sacroiliac joint; using a joint probe to identify thesacroiliac joint; inserting a guide wire through a canal in the jointprobe and into the sacroiliac joint; slotting a surgical channel deviceover the guide wire, the surgical channel device having a workingchannel; creating a void in the sacroiliac joint, wherein creating thevoid comprises displacing a portion of the patient's ilium and a portionof the patient's sacrum with an inserted end of the working channel,inserting a drill bit into the working channel, and drilling the voidinto the sacroiliac joint; inserting a fusion implant into the void,wherein the fusion implant includes a plurality of fixation elements andis configured to substantially compress, fix, and fuse the patient'silium to the patient's sacrum; and engaging the fixation elements of thefusion implant with bone tissue in the articular surfaces of thepatient's ilium and sacrum.

In some embodiments, the present invention relates to a method includingpreparing the patient for surgery (e.g., positioning the patient in aprone position to provide the surgeon access to the SI joint, general orlocal anesthesia, and the like), making a small incision over the top ofthe iliac wing from a posterior approach, locating the SI joint and anincision point for access to the SI joint (e.g., by blunt fingerpalpation), insertion of a pin or wire to create an incision, insertionof a dilator over the pin and impacting the dilator to dilate theincision to a width through which instruments may be passed, inserting afirst working channel of a double-barreled, double-angled exposuredevice over the dilator and inserting a second working channel of saidexposure device in the incision over the iliac wing, securing the firstand second working channels in position with fixing pins, removing thedilator, inserting a drill bit apparatus through each of the first andsecond work channels, using the drill bit apparatus in the first workingchannel to displace bone in the SI joint thereby creating a void, usingthe drill bit apparatus (or a second drill bit apparatus) in the secondworking channel to drill a hole in the iliac crest and the S1 vertebraof the sacrum, removing the drill bit apparatus, loading a graft onto aninserter and inserting the graft and inserter into the first workingchannel until the graft is positioned proximal to the void in thepatient's SI joint, inserting an impactor into the first working channeland applying force to displace the graft into the void in the patient'sSI joint, inserting a joint fusion device coupled to a fusion deviceinserter into the second working channel and implanting said jointfusion device in the hole in the iliac crest and the sacrum, removingall instruments, and closing the incisions.

Additional objects of the invention will be apparent from the detaileddescriptions and the claims herein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an anterior view of the bony anatomy of the pelvis and sacrum.

FIG. 2 is a posterior view of the bony anatomy of the pelvis and sacrum.

FIG. 3 is a right lateral view of the bony anatomy of the pelvis andsacrum.

FIG. 4 is a left lateral view of the bony anatomy of the pelvis andsacrum.

FIG. 5 is a superior view of the bony anatomy of the pelvis and sacrum.

FIG. 6 is an inferior view of the bony anatomy of the pelvis and sacrum.

FIG. 7 is an oblique view of the right sacroiliac joint.

FIG. 8 is a perspective view of a joint probe.

FIG. 9 is an enlarged view of the joint probe in FIG. 8.

FIG. 10 is an end view of the joint probe in FIG. 8.

FIG. 11 is a perspective view of a guide pin.

FIG. 12 is an end view of the guide pin in FIG. 11.

FIG. 13 is a perspective view of a joint cutting instrument.

FIG. 14 is an enlarged view of the joint cutting instrument in FIG. 13.

FIG. 15 is an end view of the joint cutting instrument in FIG. 13.

FIG. 16 is a perspective view of a t-handle addition for a joint cuttinginstrument.

FIG. 17 is an end view of the t-handle addition in FIG. 16.

FIG. 18 is a perspective view of a joint cutting assembly.

FIG. 19 is an exploded, perspective view of the joint cutting assemblyin FIG. 18.

FIG. 20 is a perspective view of a drill bit.

FIG. 21 is an end view of the drill bit in FIG. 20.

FIG. 22 is a perspective view of a fixation pin insertion assembly.

FIG. 23 is an exploded, perspective view of the fixation pin insertionassembly in FIG. 22.

FIG. 24 is a side view of a box chisel.

FIG. 25 is a side view of a rasp.

FIG. 26 is a perspective view of a bone graft impactor.

FIG. 27 is a perspective view of a surgical tool according to anembodiment of the present invention.

FIG. 28 is a side view of a surgical tool according to an embodiment ofthe present invention.

FIG. 29 is a top view of a surgical tool according to an embodiment ofthe present invention.

FIG. 30 is a perspective view of a surgical tool according to anembodiment of the present invention.

FIG. 31 is a perspective view of a surgical tool according to anembodiment of the present invention.

FIG. 32A is a close-up perspective view of the distal end of a surgicaltool according to an embodiment of the present invention, where thesurgical includes tangs at a distal end thereof.

FIG. 32B is a close-up perspective view of the distal end of a surgicaltool according to an embodiment of the present invention, where thesurgical includes tangs at a distal end thereof.

FIG. 33 is a perspective view of a surgical tool according to anembodiment of the present invention.

FIG. 34 is a side view of a surgical tool according to an embodiment ofthe present invention.

FIG. 35 is a top view of a surgical tool according to an embodiment ofthe present invention.

FIG. 36 is a bottom view of a surgical tool according to an embodimentof the present invention.

FIG. 37 is an isolated, top view of a surgical tool according to anembodiment of the present invention.

FIG. 38 is a perspective view of a fusion implant inserter for use witha surgical tool according to an embodiment of the present invention.

FIG. 39 is a perspective view of a fusion implant inserter engaged witha fusion implant for use with a surgical tool according to an embodimentof the present invention

FIG. 40 is a cross sectional view of one barrel of a surgical toolaccording to an embodiment of the present invention.

FIG. 41 is a cross sectional, side view of one barrel a surgical toolaccording to an embodiment of the present invention engaged with afusion implant inserter.

FIG. 42 is a cross sectional, side view of one barrel a surgical toolaccording to an embodiment of the present invention engaged with afusion implant inserter.

FIG. 43 is a cross sectional, side view of one barrel a surgical toolaccording to an embodiment of the present invention fully engaged with afusion implant inserter.

FIG. 44 is a perspective view of a fixation implant assembly.

FIG. 45 is an exploded, perspective view of a fixation implant assembly.

FIG. 46 is a perspective view of a fixation implant insertion assembly.

FIG. 47 is an exploded, perspective view of a fixation implant insertionassembly.

FIG. 48 is a perspective view of an adjustable rack for attachingworking channels according to an embodiment of the present invention.

FIG. 49 is a perspective view of a fusion implant having helicalfixation elements according to an embodiment of the present invention.

FIG. 50 is a side perspective view of a fusion implant having helicalfixation elements according to an embodiment of the present invention.

FIG. 51 is a distal view of a fusion implant having helical fixationelements according to an embodiment of the present invention.

FIG. 52 is a perspective view of a fusion implant having a helicalfixation element according to an embodiment of the present invention.

FIG. 53 is a side view of a fusion implant having a helical fixationelement according to an embodiment of the present invention.

FIG. 54 is a distal view of a fusion implant having a helical fixationelement according to an embodiment of the present invention.

FIG. 55 is an oblique, posterior view of the sacroiliac joint with afusion implant having helical fixation elements placed in the sacroiliacjoint through a posterior approach according to an embodiment of thepresent invention.

FIG. 56 is a perspective view of a fenestrated sacroiliac fusion implanthaving lateral flukes according to an embodiment of the presentinvention.

FIG. 57 is a side perspective view of a fenestrated sacroiliac fusionimplant having lateral flukes according to an embodiment of the presentinvention.

FIG. 58 is an oblique, posterior view of the sacroiliac joint with afenestrated fusion implant having lateral flukes placed in thesacroiliac joint through a posterior approach according to an embodimentof the present invention.

FIG. 59 is a perspective view of an open-body, compression screwsacroiliac fusion implant according to an embodiment of the presentinvention.

FIG. 60 is a superior view of an open-body, compression screw sacroiliacfusion implant according to an embodiment of the present invention.

FIG. 61 is a side view of an open-body, compression screw sacroiliacfusion implant according to an embodiment of the present invention.

FIG. 62 is an oblique, posterior view of the sacroiliac joint with anopen-body, compression screw sacroiliac fusion implant placed in thesacroiliac joint through a posterior approach according to an embodimentof the present invention.

FIG. 63 is a perspective view of an open-body sacroiliac fusion implanthaving lateral blades according to an embodiment of the presentinvention.

FIG. 64 is a superior view of an open-body sacroiliac fusion implanthaving lateral blades according to an embodiment of the presentinvention.

FIG. 65 is a perspective view of an open-body sacroiliac fusion implanthaving detachable lateral blades according to an embodiment of thepresent invention.

FIG. 66 is a perspective view of a detached lateral blade for anopen-body sacroiliac fusion implant according to an embodiment of thepresent invention.

FIG. 67 is an oblique, posterior view of the sacroiliac joint with anopen-body sacroiliac fusion implant having lateral blades placed in thesacroiliac joint through a posterior approach according to an embodimentof the present invention.

FIG. 68 is a perspective view of an open-body sacroiliac fusion implanthaving a rotatable member with lateral flukes according to an embodimentof the present invention.

FIG. 69 is a proximal view of an open-body sacroiliac fusion implanthaving a rotatable member with lateral flukes according to an embodimentof the present invention.

FIG. 70 is a side view of an open-body sacroiliac fusion implant havinga rotatable member with lateral flukes according to an embodiment of thepresent invention.

FIG. 71 is an oblique posterior view of the sacroiliac joint.

FIG. 72 is an oblique posterior view of the sacroiliac joint and a jointprobe.

FIG. 73 is an oblique posterior view of the sacroiliac joint and a jointprobe with the joint probe identifying the SI joint.

FIG. 74 is an enlarged oblique posterior view of the sacroiliac jointand a joint probe with the joint probe identifying the SI joint.

FIG. 75 is an oblique posterior view of the SI joint and a joint probewith a guide pin marking the SI joint.

FIG. 76 is an oblique posterior view of an SI joint with a joint cuttinginstrument entering the joint.

FIG. 77 is an enlarged oblique posterior view of an SI joint with ajoint cutting instrument entering the joint.

FIG. 78 is an oblique posterior view of a surgical tool according to anembodiment of the present invention inserted into an SI joint.

FIG. 79 is an oblique posterior view of a joint cutting assembly and asurgical tool according to an embodiment of the present inventioninserted into an SI joint.

FIG. 80 is an oblique posterior view of an SI joint with a surgical toolaccording to an embodiment of the present invention and a fixation pinassembly.

FIG. 81 is an enlarged oblique posterior view displaying a fixation pinassembly and a surgical tool according to an embodiment of the presentinvention.

FIG. 82 is an oblique posterior view of a surgical tool according to anembodiment of the present invention inserted into an SI joint with theguide pins marking implant placements.

FIG. 83 is an enlarged, superior view of a surgical tool according to anembodiment of the present invention inserted into an SI joint with theguide pins marking implant placements.

FIG. 84 is an oblique posterior view of a surgical tool according to anembodiment of the present invention inserted into an SI joint with drillbits present in working channel of the surgical tool.

FIG. 85 is an enlarged oblique posterior view of a surgical toolaccording to an embodiment of the present invention inserted into an SIjoint with drill bits present in working channel of the surgical tool.

FIG. 86 is an oblique posterior view of a surgical tool according to anembodiment of the present invention inserted into an SI joint with a boxchisel inserted into a working channel of the surgical tool.

FIG. 87 is an enlarged oblique posterior view of a box chisel insertedinto an SI joint, with a working channel removed from view for clarity.

FIG. 88 is an oblique posterior view of a surgical tool according to anembodiment of the present invention inserted into an SI joint with arasp inserted into a working channel of the surgical tool.

FIG. 89 is an enlarged oblique posterior view of a rasp inserted into anSI joint, with a working channel removed from view for clarity.

FIG. 90 is an oblique posterior view of a surgical tool according to anembodiment of the present invention inserted into an SI joint with afusion implant inserter inserted into a working channel of the surgicaltool.

FIG. 91 is an oblique posterior view of a surgical tool according to anembodiment of the present invention inserted into an SI joint with animpactor inserted into a working channel of the surgical tool.

FIG. 92 is an oblique posterior view of an SI joint with a joint cuttinginstrument entering the joint.

FIG. 93 is an enlarged oblique posterior view of an SI joint with ajoint cutting instrument entering the joint.

FIG. 94 is an oblique posterior view of a surgical tool engaged with thesacroiliac joint and the iliac wing according to an embodiment of thepresent invention inserted into an SI joint.

FIG. 95 is an oblique posterior view of a joint cutting assembly and asurgical tool engaged with the sacroiliac joint and the iliac wingaccording to an embodiment of the present invention inserted into an SIjoint.

FIG. 96 is an oblique posterior view of an SI joint with a surgical tooland a fixation pin assembly engaged with the sacroiliac joint and theiliac wing according to an embodiment of the present invention.

FIG. 97 is an enlarged oblique posterior view displaying a fixation pinassembly and a surgical tool engaged with the sacroiliac joint and theiliac wing according to an embodiment of the present invention.

FIG. 98 is an oblique posterior view of a surgical tool with the guidepins engaged with the sacroiliac joint and the iliac wing according toan embodiment of the present invention inserted into an SI joint.

FIG. 99 is an enlarged, superior view of a surgical tool with the guidepins engaged with the sacroiliac joint and the iliac wing according toan embodiment of the present invention.

FIG. 100 is a superior view of guide pin placements according to anembodiment of the present invention.

FIG. 101 is an enlarged superior view of guide pin placements accordingto an embodiment of the present invention.

FIG. 102 is an enlarged, posterior view of guide pin placementsaccording to an embodiment of the present invention.

FIG. 103 is an anterior view of a surgical tool according to anembodiment of the present invention inserted into an SI joint with guidepins for guiding fusion implant placement.

FIG. 104 is a superior view of a surgical tool according to anembodiment of the present invention engaged into an SI joint with guidepins for guiding fusion implant placement.

FIG. 105 is an oblique posterior view of a surgical tool according to anembodiment of the present invention engaged with an SI joint and theiliac wing with drill bits present in working channels of the surgicaltool.

FIG. 106 is an enlarged oblique posterior view of a surgical toolaccording to an embodiment of the present invention engaged with an SIjoint and the iliac wing with drill bits present in working channels ofthe surgical tool.

FIG. 107 is an oblique posterior view of a surgical tool according to anembodiment of the present invention engaged with an SI joint and theiliac wing with a box chisel inserted into a working channel of thesurgical tool.

FIG. 108 is an enlarged oblique posterior view of a box chisel insertedinto an SI joint, with a working channel removed from view for clarity.

FIG. 109 is an oblique posterior view of a surgical tool according to anembodiment of the present invention engaged with an SI joint and theiliac wing with a rasp inserted into a working channel of the surgicaltool.

FIG. 110 is an enlarged oblique posterior view of a rasp inserted intoan SI joint, with a working channel removed from view for clarity.

FIG. 111 is an oblique posterior view of a surgical tool according to anembodiment of the present invention engaged with an SI joint and theiliac wing with an impactor inserted into a working channel of thesurgical tool.

FIG. 112 is an enlarged oblique posterior view of an impactor insertedinto an SI joint, with a working channel removed from view for clarity.

FIG. 113 is an oblique posterior view of a surgical tool according to anembodiment of the present invention inserted into an SI joint with afusion implant inserter placed in a working channel of the surgicaltool.

FIG. 114 is an oblique posterior view of a surgical tool according to anembodiment of the present invention inserted into an SI joint with animpactor inserted into a working channel of the surgical tool.

FIG. 115 is an enlarged, oblique view of a fusion implant and a fixationimplant in place in the sacroiliac joint and the iliac wing and sacrum,respectively, where the fixation implant does not pass through thesacroiliac joint.

FIG. 116 is an enlarged, superior view of a fusion implant and afixation implant in place in the sacroiliac joint and the iliac wing andsacrum, respectively.

FIG. 117 is a posterior view of a pelvis with a surgical tool accordingto an embodiment of the present invention inserted into an SI joint.

FIG. 118 is a posterior view of a pelvis with a surgical tool accordingto an embodiment of the present invention with two independent workingchannels, one inserted into an SI joint and one positioned over an iliaccrest.

FIG. 119 is a posterior view of a pelvis with a surgical tool accordingto an embodiment of the present invention with two independent workingchannels attached by an adjustable rack.

FIG. 120 is a posterior view of a pelvis with a surgical tool accordingto an embodiment of the present invention with two parallel barrels.

FIG. 121 is an enlarged posterior view showing two fusion implantsinserted in an SI joint.

FIG. 122 is a posterior view of a pelvis with a surgical tool accordingto an embodiment of the present invention with two independent workingchannels, one inserted into an SI joint and one inserted over an iliaccrest. The working channel inserted into the SI joint may have twobarrels for the placement of two fusion devices in the SI joint.

FIG. 123 is an enlarged posterior view showing two fusion devicesinserted in an SI joint and one fixation device in the ilium.

FIG. 124 is a superior view showing two fusion devices inserted in an SIjoint and one fixation device in the ilium.

FIG. 125 is a posterior view of a pelvis with two surgical toolsaccording to an embodiment of the present invention with a bilateralplacement of the two surgical tools for the placement of bilateralimplants.

FIG. 126 shows a perspective view of a fusion implant, according to anembodiment of the present invention.

FIG. 127 shows a side view of a fusion implant, according to anembodiment of the present invention.

FIG. 128 shows a cross-sectional view of a fusion implant, according toan embodiment of the present invention.

DETAILED DESCRIPTION

Reference will now be made in detail to certain embodiments of theinvention, examples of which are illustrated in the accompanyingdrawings. While the invention will be described in reference to thesefigures and certain implementations and examples of the embodiments, itwill be understood that such implementations and examples are notintended to limit the invention. To the contrary, the invention isintended to cover alternatives, modifications, and equivalents that areincluded within the spirit and scope of the invention as defined by theclaims. In the following disclosure, specific details are given toprovide a thorough understanding of the invention. References to variousfeatures of the “present invention” throughout this document do not meanthat all claimed embodiments or methods must include the referencedfeatures. It will be apparent to one skilled in the art that the presentinvention may be practiced without these specific details or features.

Reference will be made to the exemplary illustrations in theaccompanying drawings, and like reference characters may be used todesignate like or corresponding parts throughout the several views ofthe drawings.

The present invention relates to novel fusion implants and surgicaltools designed for repairing a damaged or injured sacroiliac joint in ahuman patient, and methods for using such fusion implants and tools inprocedures for repairing the damaged or injured sacroiliac joint. Morespecifically, the present invention pertains to a method forcompressing, fixing, and fusing a damaged sacroiliac joint using afusion implant having fixation element(s) (e.g., integrally formedfixation elements) and a channel or cavity for holding bonegrowth-promoting materials that provides for mechanical stability andpromotes the formation of a contiguous piece of bone from the sacrum tothe ilium. The fusion implants may be applied to the SI joint through anovel surgical tool (e.g., an exposure device) without the need foradditional patient positioning or secondary surgery.

With respect to some embodiments, an approach is described to addressthe SI joint through a posterior approach while delivering a fusionimplant device that may both compress and fix the SI joint and deliverbone growth-promoting material (e.g., autologous bone, allograft, BMP,etc.). The fusion implant may be delivered to the joint, placed betweenthe sacrum and ilium, and one or more fixation elements (e.g., integralfixation elements) of the fusion implant may be engaged with bone tissuein the articular surfaces of the sacrum and ilium of the patient tothereby compress and fix the SI joint. In some embodiments, anadditional fixation device may be delivered through the iliac wing andinto the sacrum to assist in mechanically fixing the ilium and sacrumtogether, without the fixation device entering or traversing the SIjoint.

An exemplary exposure device may include a working channel for guidingvarious surgical tools during a minimally invasive SI joint repairprocedure. The surgical tool may allow the insertion of a fusion implantinto the SI joint through the working channel in the surgical tool andguide the placement of the fusion implant into the SI joint. The toolenables a minimally invasive surgical method for repairing an SI jointthat results in a secure, consistent, and reliable fusion of the SIjoint. The surgical tool enables the insertion of the fusion implantinto the SI joint while avoiding damage to the soft and connectivetissues in and around the SI joint by closely controlling the placementof the fusion implant. The surgical tool may have a barrel or cannulathrough which the fusion implant is passed into the SI joint that has aninterior perimeter shape that is complementary to and/or accommodativeof the perimeter shape of the fusion implant. For example, and withoutlimitation, the fusion implant may have lateral fixation elements (e.g.,flukes or blades) for engaging with bone tissue in the articularsurfaces of the sacrum and/or ilium within the sacroiliac joint, and theinterior of the cannula or barrel may have an oblong or ellipticalcross-sectional shape or lateral slots such that the lateral fixationelements of the fusion implant can be passed through the barrel orcannula without obstruction. The matching of the perimeter shapes of theinterior of the barrel and the fusion implant may also allow the fusionimplant to be properly oriented for placement in the SI joint. In someexamples, and without limitation, the interior of the barrel may alsoinclude longitudinal notches that may be engaged with tabs orprotrusions on the fusion implant in order to maintain properorientation of the fusion implant within the barrel.

In some embodiments, the exposure device may include an additionalworking channel that is placed laterally to the SI working channel andover the iliac wing. The additional working channel may allow for theinsertion of a fixation device (e.g., surgical screw) into the ilium andsacrum to aid in mechanically securing the SI joint. The additionalchannel may enable the insertion of a joint fixation device (e.g., ascrew or other stabilizing device) into the ilium and sacrum such thatthe additional joint fixation device does not enter or traverse (passthrough) the SI joint, thereby further avoiding damage to connectivetissue of the SI joint.

Relevant Anatomy Description

Referring to the drawings, FIG. 1 displays the bony anatomy of thesacrum and pelvis in a frontal, or anterior, view. The SI joint 102 islocated between the ilium, or iliac wing, 100 and the sacrum 101 at thebase of the pelvis 201. Additionally, the ridgeline of the articularprocess, the lateral ala 203 and the pedicle 104 of vertebrae S1 can beobserved in this view. In FIG. 2, it can be seen that the SI joint 102is not fully exposed for direct visualization from a rear, or posterior,viewpoint due to the angled and raised iliac crest 200 of the iliac wing100. This angle provides a landmark for the entry point of the exposuredevice of the present invention at the posterior iliac crest. In FIG. 3and FIG. 4, the prominence of the iliac crest 200 is displayed, alongwith the large surface area of the iliac wing 100, while the SI joint isfully enclosed between the iliac wing 100 and the sacrum 101 andoccluded for direct visualization by the iliac wing 100. Again, thelandmark of the posterior iliac crest can be seen. From a top down view,or superior view, the sacroiliac joint 102 can be fully observed betweenthe iliac wing 100 and the sacrum 101, as shown in FIG. 5. Also shown inFIG. 5, the full sacrum 101 and specifically the vertebral body 103 ofS1. The posterior superior iliac crest and the entry point of the S1pedicle 104 can be observed in a direct line from one another (see alsoFIGS. 110-111).

In FIG. 6, it can be again observed that the SI joint is occluded fromdirect visualization due to the anatomy of the sacrum 101, the ilium 100and the pelvis 201. Therefore, the only direct visualization of the SIjoint can be achieved through an anterior, superior or posterior-obliqueview of the sacrum and pelvis. Due to major organs being present in thepelvic-sacral cavity (colon, rectum, bladder, etc.), an anterior orsuperior approach to the bony anatomy and, specifically the SI joint,presents an unreasonable risk. Lateral approaches can be performed asdescribed in Published U.S. Pat. No. 5,334,205 to Cain, entitled“Sacroiliac Joint Fixation Guide,” incorporated herein by reference andPublished U.S. Pat. No. 8,221,428 to Trieu, entitled “Sacro-iliac jointimplant system, method and instrument,” incorporated herein byreference. However, these techniques rely on non-direct confirmationmethods such as navigation and fluoroscopy to determine accuratelandmark and sacroiliac joint locations.

The present invention provides for novel surgical techniques and novelfusion implant and instrument designs which allow for a directvisualization of the SI joint by utilizing a posterior-oblique accessmethod to the anatomy as displayed in the oblique view of FIG. 7. Inthis drawing, the SI joint 102 can be clearly viewed between the rightilium 100 and sacrum 101. A corresponding joint may be exposed throughthe same approach on the left hand side. Additionally, the anatomicallandmark of the right posterior iliac crest and the corresponding accessto the S1 pedicle 104 can be seen through this approach.

Instruments

The present invention utilizes a novel exposure device and a surgicaltool kit that may be used in a novel surgical method to introduce andsecure a fusion implant in a patient's SI joint. The present inventionalso relates to novel fusion implants that may be implanted into the SIjoint, for example, by the novel surgical tools and methods of thepresent invention. Exemplary tools are described herein.

The novel exposure device may be a surgical guiding tool having aworking channel therein for guiding other surgical tools for use inrepairing an SI joint.

FIGS. 27-32B, show exemplary exposure devices 137 and 137 a foraccessing a sacroiliac joint is shown, having a working channel 239 thatmay be engaged with a posterior side of the sacroiliac joint. Theworking channels of the exposure devices may have a hollow barreltherein for passing various surgical tools that may have a shapecorresponding to (complementary to) the hollow barrel. The workingchannel may provide a guide for inserting the various surgical toolsinto the SI joint, allowing precise surgical incisions, insertions ofthe fusion implant, etc. The barrel of the working channel may have aninterior perimeter shape that is complementary to and/or accommodativeof the perimeter shape of a fusion implant may be passed into the SIjoint. The matching of the perimeter shapes of the interior of thebarrel and the fusion implant may allow the fusion implant to beproperly oriented for placement in the SI joint. For example, andwithout limitation, the exemplary exposure device 137 has a barrelhaving a substantially circular interior cross-section that mayaccommodate fusion implants that have circular cross-section (e.g., ahelical implant) or a cross-section having a greatest diameter that isless than the diameter of the interior cross-section of the barrel.

In a further example, and without limitation, the barrel exposure device137 a may have an oblong or elliptical interior cross-section 190 a,where the elongated portions of the barrel (e.g., the portions of theinterior cross-section of the barrel that near the end of the major axisof the elliptical shape) act as channels through which lateralextensions of a fusion implant (e.g., a fusion implant having flukes orblades) may pass without obstruction. The interior of the barrel mayhave other shapes as well. For example, and without limitation, theinterior perimeter of the barrel may have two lateral slots spaced atabout 180° from one another in order to accommodate two lateral flukes,hooks, or blades extending from a body of an SI fusion implant. Theworking channel 239 may also have one or more pin guide slots 139 on oneor more sides thereof for insertion of fixing pins to immobilize theexposure device 137 or 137 a when it is engaged with the SI joint. Inother implementations, and without limitation, a stabilizing arm (e.g.,a retractor arm—not shown) may be engaged with a handle 140 and/or slot141 in the handle in order hold the exposure device in a static andstable position.

The working channel 239 may have one or more windows 138 in the sides ofthe hollow barrel allowing the progress of a tool inserted therein to beobserved through the one or more windows. For example, a surgicalimplement (e.g., a dilator) inserted into the hollow barrel of workingchannel 239 may have notches and/or unit markings on a side thereof thatare visible through the one or more windows 138, allowing the progressand depth of the surgical implement to be precisely known. The windows138 may also allow access to the surgical implements inserted into theworking channel. If a surgical implement becomes difficult to removeduring a surgical procedure due to the presence of fluid in the hollowbarrel of the working channel (e.g., creating suction), appropriatetools can be used to access the surgical instrument through thewindow(s) 138 to aid in the removal of the surgical implement.

Referring to FIG. 29, the hollow barrel of the working channel 239 mayhave a slot 146 (e.g., a timing feature) that arrests the progress of asurgical implement inserted into the hollow barrel of the channel. Theslot 146 prevents the surgical implement from advance too far into theSI joint or the ilium and sacrum, thereby preventing damage to thetissue of the patient. The surgical implements used in connection withthe exposure device 137 may have a protrusion that is complementary tothe slot 146, such that the slot is effective in controlling a depth towhich the surgical implement can be inserted. The slot 146 also mayensure that such surgical implements having a complementary protrusionare and remain properly oriented in the hollow barrel of the workingchannel, with no axial movement, during the surgical procedure.

The hollow barrel of the working channel may also have guiding slotstherein for properly aligning instruments (e.g., a fusion implantinserter, an impactor, etc.) and/or fusion implants for passage throughthe hollow barrel. The guiding slots may engage notches or protrusionson the instruments or implants such that the notches or protrusionsslide along the guiding slots as the instrument or fusion implant isadvanced through the hollow barrel. For example, and without limitation,guiding slots 146 a are shown in the hollow barrel of exposure device137 a in FIG. 31. The guiding slots 146 a are located at 180° relativeto one another in the hollow barrel, but the invention is not limited tosuch an arrangement. Various implementations of the exposure device ofthe present invention may have one or more guiding slots (e.g., 1, 2, 3,etc.) and they may be arranged in various spatial arrangements withinthe hollow barrel.

The insertable end 142 of the working channel 239 may have a roundedcircular or oblong geometry that prevents or reduces damage to the softand connective tissues in and around the posterior side of the SI joint.Guide channels having other shapes (e.g., rectangular or square) maydamage soft tissues around the SI joint when the guide channel isinserted therein. The round geometry of the insertable end 142 favorablyreduces or prevents such damage. The round or circular insertable end142 may also have a tapered or rounded profile, which may further aid inreducing or preventing damage to the soft and connective tissues aroundthe SI joint. It is to be appreciated that the present invention is notlimited to working channels having round, circular, or rounded ends. Theworking channels may have other perimeter shapes circular, oval,triangular, polygonal (pentagonal, hexagonal, etc.), Reuleaux shapes,and other applicable shapes.

The insertable end of the working channel may also include one or moreprongs or tangs that extend beyond the end of the hollow barrel. The oneor more prongs or tangs may allow the working channel to be more easilycentered in the SI joint (e.g., with the tangs aligned along the planebetween the articular surfaces of the SI joint), and may also serve tohelp stabilize the position of the working channel in the SI joint. Forexample, and without limitation, FIGS. 30, 32A, and 32B show embodimentsof an exposure device that includes tangs 180 a and 180 b extending fromthe distal, insertable end of exposure devices 137 b and 137 b. Thetangs 180 a and 180 b are positioned 180° relative to one another on theend of the hollow barrel, but the invention is not limited to such anarrangement. In some embodiments (e.g., an embodiment exemplified by 137b shown in FIG. 32A), and without limitation, the tangs 180 a and 180 bmay be included at the ends of the major axis of the oblong (e.g.,elliptical) end of the working channel, which may be used with animplant having lateral fixation elements such as flukes that may berotated into the bone tissue after being placed in the SI joint. Inother embodiments (e.g., an embodiment exemplified by 137 c shown inFIG. 32B), and without limitation, the tangs 180 a and 180 b may beincluded at the ends of the minor axis of the oblong (e.g., elliptical)end of the working channel, which may be used with an implant havinglateral fixation elements such as lateral plates that may be inserteddirect into the bone tissue of the SI joint.

The working channel may have other additional features such as handles140 and slots 141 therein (e.g., for inserting handle extensions, etc.),as well. Additionally, the handle 140 may also be attachable to astabilizing structure (e.g., a table or surgical arm,retractor/stabilizing arms, etc.) to prevent movement of the exposuredevice or surgical implements engaged therewith during surgicalprocedure. It is to be appreciated that the above description of theexposure tool does not limit the present invention, and other featuresare contemplated in and within the scope of the present invention.

In some embodiments the invention may comprise a double-barreled workingchannel having side by side (e.g., parallel) hollow barrels, each ableto receive and guide surgical implements. The two barrels may have asame or different length. In reference to FIG. 120, a double-barreledworking channel 295 may have first and second parallel barrels. Workingchannel 295 may allow multiple fusion implants to be inserted into an SIjoint. In such embodiments, the additional working channel of thedouble-barreled working channel may have similar features as describedabove with respect to the working channel 239.

In some embodiments of the present invention, and without limitation,the exposure device may be a surgical guiding tool having two workingchannels therein for guiding other surgical tools for use in repairingan SI joint. The two working channels may be attached to one another bya connecting member, such as a bar or a rack. The bar may have a bend orangle therein that positions the two working channels at an angle (withrespect to their longitudinal axes) relative to one another in a rangeof 0° to 180°. In some embodiments, the angle between the two workingchannels may be acute (e.g., about 30° to about 50°, or any angle inthat range, such as about 45°). The angled positions of the two workingchannels allows one working channel to be positioned over the SI jointand the second working channel to be positioned over the ilium (e.g.,the iliac wing) simultaneously and snugly, enabling the insertion of onemore joint fusion implants into the SI joint and a joint fixation device(e.g., a bone screw) into the ilium and sacrum in a single procedurewith a simple tool, without the need to reposition the surgical tool toinsert either the joint fusion implants or the fixation device. Infurther embodiments, the relative angle of orientation of the twoworking channels may be a right angle or may be obtuse, depending on thedesired insertion point on the ilium. If a different entry point for ajoint fusion device is desired, the relative orientation angle of thetwo working channels may be in a range of about 45° to about 180° (e.g.,about 90° to about 180°, about 45° to about 135°, about 90° to about120°, or any value or range of values therein). For example, if thedesired entry point on the ilium is more lateral or anterior, the angleof orientation between the two working channels may be 90° or greater.

Referring to FIGS. 33-37, a dual working channel exposure device 300 isshown having a connecting bar 337 connecting a first working channel 339and a second working channel 350. The connecting bar 337 may have a bendor angle 343 between the first and second working channels 339 and 350.In some implementations, and without limiting the invention, the bend343 may have an obtuse angle in a range of about 110° to about 160°(e.g., about 135° or any value therein). In some implementations, andwithout limiting the invention, the bend 343 may result in the first andsecond working channels being positioned at an acute angle relative toone another that may be complementary to the obtuse angle of the bend343. In alternative implementations, and without limitation, theconnecting bar may have a lockable joint therein between the first andsecond working channels 339 and 350 that may be adjusted to have anangle in a of about 90° to about 180° (e.g., about 135° or any valuetherein). The angle of the connecting bar 343 is configured toaccommodate the contour of the pelvis between the ilium and the SI jointsuch that the first working channel 339 can be engaged with a posteriorside of the sacroiliac joint and the second working channel 350 can beengaged with a posterior portion of the ilium simultaneously.

The connecting bar 337 may also have a second angle therein, as shown inthe top perspective of FIG. 35 and the bottom perspective of FIG. 36.The first and second working channels 339 and 350 may be position at anangle between about 5° and about 40° (e.g., about 15°, or any angletherein). To further illustrate, the bar 343 may be angled such that thelongitudinal axes of the first and second working channels 339 and 350may run along different, but parallel planes. Thus, the working channels339 and 350 are positioned at an acute angle relative to one anotherfrom a side perspective (e.g., FIG. 34), and on parallel planes relativeto each other from top or bottom perspective (e.g., FIGS. 35 and 36).The additional angle in the connecting bar 343 may aid in positioningthe second working channel 350 on the ilium when the first workingchannel is engaged with the SI joint, such that the second workingchannel 350 is positioned over the iliac wing, close to the iliac crest.The position and angle of the second working channel 350 may allow theinsertion of a bone fusion device (e.g., a bone screw) through the iliumand the sacrum (e.g., the S1 vertebrae) through the hollow barrel of thesecond working channel 350, such that the bone fusion device does nottraverse the SI joint (e.g., it is inserted anteriorly to the SI joint).

Each working channel may have a hollow barrel therein for passingvarious surgical tools that have a shape corresponding to (e.g.,complementary to) the hollow barrel. The working channels provide aguide for inserting the various surgical tools into the SI joint and theilium, allowing precise surgical incisions, insertions of fusionimplants, bone-growth promoting material, etc. The working channelposition over the SI joint may have a hollow barrel having an oblong orelliptical internal cross-section or other shape for accommodatingfusion implants having one or more lateral fixation elements, asdiscussed above. Each of the first and second working channels 339 and350 may have one or more pin guide slots 349 on a side thereof forinsertion of fixing pins to immobilize the exposure device 300 when itis engaged with the SI joint and the ilium. The first and second workingchannels may also each have one or more windows 338 in sides of thehollow barrels allowing the progress of a tool inserted therein to beobserved through the one or more windows, and allow access toinstruments in the working channels through the windows, similarly towindow 138 described above.

Referring to FIG. 37, the hollow barrels of the first and second workingchannels 339 and 350 may have a slot 346 (e.g., a timing feature) thatarrests the progress of a surgical implement inserted into the hollowbarrel of the channel. The slot 346 may prevent the surgical implementfrom advance too far into the SI joint or the ilium and sacrum and mayensure that surgical tools passed through the hollow barrels remainproperly oriented, with no axial movement, thereby preventing damage tothe tissue of the patient. The surgical implements used in connectionwith the dual working channel surgical tool may have a protrusion thatis complementary to the slot 346, such that the slot is effective incontrolling a depth to which the surgical implement can be inserted.

The insertable end 342 of the first working channel 339 may have a roundor circular geometry that prevents or reduces damage to the soft andconnective tissues in and around the posterior side of the SI joint. Theround or circular insertable end 342 may also have a tapered or roundedprofile, which may aid in reducing or preventing damage to the soft andconnective tissues around the SI joint. The second working channel 350may also have circular and/or rounded or tapered insertable end 342, aswell. It is to be appreciated that the present invention is not limitedto working channels having round, circular, oblong or otherwise roundedends. The insertable end of the working channel 339 may also include oneor more prongs or tangs that extend beyond the end of the hollow barrel,as discussed above. The one or more prongs or tangs may allow theworking channel to be more easily centered in the SI joint (e.g., withthe tangs aligned along the plane between the articular surfaces of theSI joint), and may also serve to help stabilize the position of theworking channel in the SI joint.

The first and second working channels may have other additional featuressuch as handles 340 and slots 341 therein (e.g., for inserting handleextensions), as well. It is to be appreciated that the above descriptionof the surgical tool does not limit the present invention, and otherfeatures are contemplated in the present invention.

In some embodiments the invention may comprise one or more separateworking channels that may be used in a similar manner to the dualworking channel exposure device. In reference to FIG. 119, the inventionmay include first and second working channels 290, which can beindividually positioned, for example, with one inserted into theposterior of the SI joint, and another positioned over the iliac wing.In such embodiments, the individual working channels may have the samefeatures described above with respect to the dual working channelexposure devices described herein, except for the connecting bar 343 andthe features particular thereto.

In some embodiments, the invention may include a kit or set of surgicalimplements and one or more joint fusion implants and joint fixationdevices (e.g., surgical screws) that are associated with one or more ofthe exposure devices described above. Various tools may be included insuch a set, including a joint cutting instrument (e.g., dilator), guidepins, guide pin assemblies, a drill, drill bits, a rasp, a box chisel,an inserter, and an impactor. Each of such tools may correspond to theexposure devices described herein. For example, the joint cuttinginstrument, the drill bits, the rasp, the box chisel, the inserter, andthe impactor each may have a shape that is complementary to a hollowbarrel of the exposure device, allowing each instrument to be insertedinto the hollow barrel flush and in the proper orientation, without roomto deviate from the path of the barrel. Thus, the working channel of theexposure device may act as precise guides for the surgical implementsdescribed above.

These surgical implements may be made of any suitable material,including medical grade plastics, metals, or alloys. In someembodiments, and without limitation, the tools are single use, in otherembodiments the tools may be reused (and autoclaved, cleaned orotherwise suitably disinfected for further use). The tools may havevarious configurations, including those that differ from those depictedand specifically described herein.

The implements may include a joint probe capable of being used to locatean insertion point in an SI joint for a fusion implant. The joint probemay have a hollow channel therethrough for inserting a guide wire intothe SI joint once the joint probe is properly positioned in theinsertion point. Referring to FIGS. 8-11, the joint probe may have arounded tip 111 for locating the insertion point, a shaft 112, and ahandle 110. A hollow channel 113 run through the length of the jointprobe to allow a guide wire to be inserted therethrough and into the SIjoint.

The set of tools may also include guide pins for securing the exposuredevice to the SI joint and the ilium. Referring to FIGS. 11-12, theguide pin 115 may have shaft that corresponds to the central channel ofthe joint probe and may be inserted into the SI joint through thedilator, to guide tools and implements subsequently positioned in saidSI joint.

The set of surgical implements may include a dilator, which may be anydevice or structure capable of dilating an incision made in a human orother animal. FIGS. 13-19 illustrate an example of a dilator system thatmay be included in the present invention. Dilator 116 may be made of anysuitable material and may have any suitable dimensions andconfiguration. In the depicted example, dilator 116 has a distal end117, a proximal end 118, and a shaft therebetween. Proximal end 118 mayhave any configuration suitable to dilate an opening or incision, forexample an incision made by a pin or wire in the patient's flesh anddilate that incision to increase its size. The proximal end 118 may betapered, coming to a point at its end. The distal end 117 may befaceted, allowing it to be engaged with a grooved end 120 of a T-handle119. A dilator assembly, an example of which is shown in FIGS. 18 and19, allows the dilator to be spun or otherwise manipulated to adjust thesize of an incision. The dilator 116 (and the t-handle 119) may have acentral channel 213 running down its length that may allow a guide wireor pin to be inserted therethrough into the incision.

Fixing pins 126 and a fixing pin handle 125, as shown in FIGS. 22-23,may be included in the set of tools that correspond to the pin guideslots 139 on sides of the working channels of the exposure devices. Theguide pins may also have a sharp and/or threaded end 115 for piercingbone and other tissues. The fixing pins may correspond to the pin guideholes on sides of the working channels (e.g., pin holes 139, and 349) ofthe exposure devices described above. The fixing pins can be used tosecure the working channels in a desired position over the SI joint orthe ilium.

A drill 122, as shown in FIGS. 20-21, may be included in the set toallow for bone preparation for fusion implant insertion. The drill mayhave a thread portion 124 with numerous designs in order to provide ahole with the desired female thread cut in the desired anatomy. Thedrill may also be designed to be attached to power instruments, a handdrill or a handle. Without limiting the invention, FIG. 20 an exemplarydrill having a Jacob's chuck connection 123 so that it may be attachedto a powered drill for quick preparation. Additionally, the drill mayhave a central channel 124 running down its length that may allow aguide wire or pin 114 to be inserted there through into the incision asseen in FIG. 21.

A chisel 131, as shown in FIG. 24, may be included in the set to providean opening in the bone with desired dimensions on its distal tip 134 tobetter facilitate entry for the fusion implant. The distal tip 134 mayhave a tapered nose in order to self-distract its way in between thesacrum and ilium. The distal tip 134 may also have cutting edges to diginto the bone and remove it from the surgical site. The chisel may beused to penetrate the cortical tissue of the sacrum and ilium to allowanchoring portions of the joint fusion implants of the present inventionto penetrate the bone tissue and thereby anchor the fusion implant inthe joint. The distal tip 134 may also have a containment device forremoval of surgical site bone and windows may exist in the containmentdevice to collect bone debris and remove the bone debris after removalfrom surgical site. The distal tip 134 may be undersized to a fusionimplant to be inserted in order to ensure full bony contact on all sidesof the fusion site. The chisel may have an outer diameter, as seen inFIG. 24, that matches the inner diameter of a working channel (e.g.,working channels 239, 339, and 350) to keep the chisel directed in anaxial plane for desired implant preparation. The chisel may have atiming feature 133 that mates with a female timing feature (e.g., timingfeature 146 or 346) on the inside of a working channel to keep thechisel from plunging too far into the surgical site and to further keepthe chisel in the proper orientation for desired implant sitepreparation.

Additionally, a rasp 132, as shown in FIG. 25, may be included in theset to provide an opening in the bone with desired dimensions on itsdistal tip 135 to better prepare the bone for a fusion site for thefusion implant. The distal tip 135 may have a tapered nose in order toself-distract its way in between the sacrum and ilium. The distal tip135 may have aggressive teeth which can scrape the bone to help preparethe bone surface for receiving anchoring portions of joint fusionimplants of the present invention. The rasp may have an outer diameteras seen in FIG. 25, that matches the inner diameter of a working channel(e.g., working channels 239, 339, and 350) to keep the rasp directed inan axial plane for desired implant preparation. The rasp may have atiming feature 133 that mates with a female timing feature (e.g., timingfeature 146 or 346) on the inside of a working channel to keep theinstrument from traveling too far into the surgical site and to furtherkeep the instrument in the proper orientation for desired implant sitepreparation.

One or more impactors, such as impactor 136 shown in FIG. 26, may beincluded in the surgical implements, as well. The impactor may have acylindrical proximal end, like a hammer. The impactor may be included inthe set to facilitate secondary impaction and movement of a fusionimplant and, optionally, to advance bone-fusion promoting materials inthe SI joint in front of and/or behind the implant to better prepare thesurgical site and to promote fusion of the SI joint. The impactor mayhave an outer diameter, as seen in FIG. 26, that matches the innerdiameter of a working channel (e.g., working channels 239, 339, and 350)to keep the instrument directed in an axial plane for desired surgicalsite preparation.

Inserters for fusion devices may be included in the set to facilitatedelivery of implants or grafts into the sacroiliac joint and into theilium and sacrum. Without limiting the invention, FIG. 38 shows anexemplary fusion inserter 147 can be used to deliver a fusion implant ofdesired materials such as PEEK, metal or biologic material into thesurgical site. As seen in FIG. 38, the inserter may have a thumbwheel148 that is attached to a spring element 150. When thumbwheel 148 istightened, spring element 150 may be tightened down onto an fusionimplant to keep the implant from disengaging from the inserter duringimplantation. Fork arms 149 may enter recesses on a proximal end of thefusion implant to keep the implant from losing its desired orientationduring insertion. Upon desired placement of the fusion implant,thumbwheel 148 may be loosened and the spring element 150 detaches fromthe implant, leaving the implant in the desired position. Withoutlimiting the invention, FIG. 39 shows an inserter 147 engaged with anexemplary fusion implant 151. In this example, and without limitation,the implant 151 has notices on the lateral sides thereof that may beengaged by the fork arms of inserter 147.

The inserter 147 may have an outer diameter as seen in FIG. 38, thatmatches the inner diameter of a working channel (e.g., working channels239, 339, and 350) to keep the inserter directed in an axial plane fordesired implant preparation. The inserter may have a timing feature 150that mates with a female timing feature (e.g., timing feature 146 or346) on the inside of a working channel (e.g., working channels 239,339, and 350) to keep the instrument from traveling too far into thesurgical site and to further keep the instrument in the properorientation for desired implant site preparation.

Instrument kit of the present invention may additionally include adriver (e.g., a manual or electrically powered driver, etc.) forinserting joint fixation devices, such as surgical screws, into bonetissue in the articular surfaces of the SI joint and/or into the bonetissue of the ilium and sacrum without the fusion device traversing theSI joint. For example, a bone screw 158 (e.g., a compression screw) maypassed through a working channel positioned over an iliac wing anddriven through the ilium and sacrum with fixation device driver 125. Inother examples, surgical screws 603 and 604 shown in FIGS. 59-61 may beinserted through a working channel over the SI joint and passed intofusion implant 600 at an oblique angle by a special driver having auniversal joint or a flexshaft (not shown) that is operable drive thescrews into the articular surfaces of the sacrum and ilium at obliqueangles in order to secure the fusion implant 600 in the SI joint.

The surgical kits of the present invention may also include one or moreof the joint fusion implants disclosed herein, and a particular kit mayinclude an exposure device having an internal cross-section thatcorresponds to a shape of the one or more joint fusion implants that areincluded in the kit. The surgical kits may also include one or morejoint fixation devices (e.g., surgical screws) for fixing the ilium andsacrum together.

It is to be appreciated that additional surgical tools or implements maybe used with the present working channels, and that the invention is notlimited to use of the implements described in this section.

Fusion Implants

The present invention also relates to fusion implants that includefixation element(s) that mechanically secure and compress the SI joint,and deliver bone-growth promoting material into the SI joint tofacilitate the formation of a contiguous piece of bone from the sacrumto the ilium. The fusion implants of the present invention may beapplied to the sacroiliac joint through the novel exposure devicesdescribed herein. The novel posterior exposure devices and the combinedfixation and stability, compression, and fusion functionalities of thefusion implants of the present invention may allow for posteriorapproach that may eliminate the need for patient repositioning orfurther incisions, resulting in less surgery time, less morbidity, andimproved recovery time for the patient. Thus, the surgical methods andfusion implants of the present invention allow for a minimally invasivemethodology.

To create fixation, stability, and compression from a posterior implantin the sacroiliac joint, the fusion implants of the present inventiondraw together, connect, and hold the articular surfaces of both thesacrum and ilium together, while stimulating a fusion of the articularsurfaces. The joint fusion device may create stress and pressure on thebone tissue by mechanically drawing the bones together, and may therebyutilize bone remodeling (e.g., as according to Wolff's Law) to promotestable and robust bone fusion in the targeted joint. The variousembodiments of the fusion implants of the present invention all containmechanisms that connect both the sacrum and the ilium independently,while using a body thereof to bridge across the two bones for a fusionsite. Each of the various embodiments of the fusion implant may includea channel or cavity that may be used to hold bone-growth stimulatingmaterials in the form of autologous bone, allograft, BMP, etc.

In some embodiments of the fusion implant, and without limitation, thefusion implant may have one or more helical anchors for insertion intobone tissue. In such embodiments, the fusion implant may also include achannel or cavity for holding bone growth-enhancing material forpromoting fusion of adjacent bones held together by the fusion implant.For example, and without limitation, a fusion implant may include asingle helix or multiple helices (e.g., 2 or 3 helices) that may beconcentric and/or interwoven. In some embodiments, and withoutlimitation, the helical path of the helical fixation anchors may have auniform diameter from their proximal end to the distal end thereof.However, in other embodiments, and without limitation, the helical pathof the helical fixation anchors may taper outward or inward from theproximal end to the distal end of the helical path to create a conicalshape to the helical path.

Without limiting the invention, FIGS. 49-51 show an exemplary fusionimplant 400 having two helical anchors. The implant 400 has a body 401attached to two helical anchors 403 and 404, which may be concentric andinterwoven. Each of the helical anchors 403 and 404 may have a distalcutting edge 405 that may be operable to penetrate bone tissue in jointtargeted for fusion. The distal cutting edges of each of the helicalanchors 403 and 404 may be on opposite sides of the fusion implant 400such that as the implant is advanced into the SI joint, the helicalanchor 403 engages the ilium and helical anchor 404 engages the sacrum.The body 401 of the fusion implant 400 may have notches or slots 402 ina perimeter thereof that may be engaged by a fusion implant inserter ordriver as described herein (e.g., by fork arms 149). The implant 400 mayhave a outer diameter in a range of about 8 mm to about 20 mm (e.g.,about 12 mm to about 18 mm, or any other value or range of valuestherein). The implant may be paired with a exposure device having ahollow barrel with an internal cross-section that corresponds to thediameter and cross-sectional shape of the implant.

In other embodiments, and without limitation, the fusion implant mayhave a single helix attached to the body of the fusion implant. Forexample, and without limitation, FIGS. 52-54 illustrate an exemplaryfusion implant 400 a that may include a single helical anchor 403 a. Thefusion implant 400 a has a body 401 a attached to the helical anchor 403a, which may have a distal cutting edge 405 a that may be operable topenetrate bone tissue in joint targeted for fusion. After being insertedinto the SI joint the body 401 a may be rotated in a range of about 180°to about 360° (e.g. about 270°, or any value or range of values therein)such that helical anchor 403 a may engage the articular surfaces of boththe ilium and the sacrum so that the fusion implant can compress thebones together and stabilize the SI joint. The body 401 a of the fusionimplant 400 a may have notches or slots 402 a in a perimeter thereofthat may be engaged by a fusion implant inserter or driver as describedherein (e.g., by fork arms 149).

The process of inserting and advancing the fusion implant 400 (or 400 a,or other related embodiments) may be performed by one or more tools thatengage the notches or slots 402 (or 402 a). An inserter (e.g., inserter147) may be used to initially place the fusion implant 400 (or 400 a, orother related embodiment) in a desired position between the sacrum andilium, and the inserter may be subsequently rotated to engage thehelical anchors with the bone tissue of the articular surfaces of thesacrum and ilium. For example, and without limitation, a driving toolmay be attached to the inserter to aid in rotating the inserter. As thefusion implant is rotated, the sacrum and ilium bones may be pulledtowards each other and the sacroiliac joint may be compressed andstabilized. Cutting edges 405 may be pierce the bone tissue (e.g.,cortical and/or cancellous/spongy bone tissue) of the sacrum and ilium.As shown in FIGS. 49-50, but without limitation, the cutting edges 405of the helical anchors 403 and 404 are aligned with the notches 402 forreceiving the inserter tool. This alignment may be included in order toposition the cutting edges in a precise position within the joint. Forexample, the alignment allows the surgeon to control insertion of thecutting edges such that the cutting edge of one of the helical anchorsis positioned at the targeted articular surface of the sacrum and thecutting edge of the other helical anchor is positioned at the targetedarticular surface of the ilium. In such implementations, the position ofthe cutting edges can be controlled by the aligning the inserter withthe plane of the joint (the plane between the articular surfaces), andthereby placing the cutting edges in close proximity to the targetedarticular surfaces such that they engage and penetrate the articularsurfaces immediately upon rotation of the inserter. Other embodiments ofthe fusion implant (e.g., those having a single helical anchor, orflukes, claws, etc.) may also be inserted such that the portion of thefusion implant for engaged with the bone tissue is positioned adjacentto the targeted articular surface when inserted into the joint and priorto rotation of the implant.

In some implementations, and without limitation, surgical tools (e.g., adrill, chisel, rasp, etc.) may be used to remove cortical tissue fromthe targeted articular surfaces of the sacrum and ilium to prepare(“prep”) the articular surfaces for engagement with the fusion implantbefore the fusion implant is inserted into the joint, allowing thehelical anchors of the fusion implant to more easily pierce the bonetissue of the sacrum and ilium. In such implementations, and withoutlimitation, the fusion implant may be inserted into the joint such thatthe cutting edges of the fusion implant may be aligned with and adjacentto the prepped articular surfaces.

In some implementations, and without limitation, the fusion implant mayinclude a cannulated channel or cavity that allows for the addition ofbone growth-stimulating materials into the targeted joint. For example,and without limitation, the fusion implant 400 (or 400 a, or otherrelated embodiment) may include a cannulated channel (e.g., 406) runningfrom a central hole in the proximal end of body (e.g., 401) through theone or more helical anchors (e.g., 403 and 404) to the distal end(s) ofthe one or more helical anchors (e.g., 403 and 404). The cannulatedchannel may be packed with bone growth-stimulating materials (e.g.,autologous bone, allograft, BMP, etc.) to stimulate bone growth acrossthe fusion implant and the joint that may lead to fusion of the sacrumand ilium. Without limiting the invention, the bone growth-stimulatingmaterials may be inserted into the channel through a proximal hole inthe body after the fusion implant is set into desired operativeposition. In other implementations, the bone growth-stimulatingmaterials may be present in the channel prior to insertion of the fusionimplant into the SI joint.

As an example, and without limitation, FIG. 50 provides a side view ofthe fusion implant 400 in which the length of the cannulated channel 406can be seen running from the proximal hole in the body 401 to the distalends of the helical anchors 403 and 404. FIG. 51 provides a bottom viewof the implant 400 and shows the complete cannulated channel 406 and theconcentric and interwoven pattern of the helical anchors 403 and 404.However, it should be understood that the present invention is notlimited to the particular arrangement of the exemplary helical anchors403 and 404 in FIGS. 49-51. For example, and without limitation, FIG. 53provides a side view of fusion implant 400 a in which the length ofcannulated channel 406 a can be seen running from a proximal hole in thebody 401 to the distal end of the helical anchor 403 a. FIG. 54 providesa bottom view of fusion implant 400 a showing the complete cannulatedchannel 406 a.

FIG. 55 displays the fusion implant 400 in its desired operativeposition in the sacroiliac joint 102, where helical anchors 403 isengaged with the ilium 200 and anchor 404 is engaged with the sacrum101. The implant may create stability and fixation across the joint,compression in the joint, and bone growth-promoting material can beadded to the cannulated channel 406 to aid in fusion of the sacrum andilium at the site of the fusion implant. It is to be understood thatother related embodiments (e.g., fusion implant 400 a) may be placed inthe joint in the same manner. It is also to be understood that multiplefusion implants may be placed into the sacroiliac joint from theposterior approach. For example, and without limitation, thedouble-barreled exposure device 295 shown in FIGS. 118-119, which hastwo side by side (e.g., parallel) working channels may be used tointroduce two fusion implants into the SI joint.

In other embodiments of the fusion implant, and without limitation, thefusion implant may have a central body with flukes, claws, hooks, orother bone engaging structures attached thereto. Additionally, thecentral body may have a channel or cavity in which bone growth-enhancingmaterials may be included. Without limiting the invention, FIGS. 56-57show an exemplary embodiment of a fusion implant 500 having lateralflukes 503 and 504 for engaging with the targeted articular surfaces ofthe SI joint. Each of the lateral flukes 503 and 504 may have a distalhooking ends 505 that may be operable to penetrate bone tissue in jointtargeted for fusion. The distal cutting edges of each of the lateralflukes 503 and 504 may be on opposite sides of the fusion implant 500such that as the fusion implant is advanced into the SI joint, thelateral fluke 503 engages the ilium and lateral fluke 504 engages thesacrum. The proximal end of the body 501 of the fusion implant 500 mayhave notches or slots 502 in a perimeter thereof that may be engaged bya fusion implant inserter or driver as described herein (e.g., by forkarms 149). The notches or slots 502 may allow the inserter to turn thefusion implant 500 (e.g., in a clockwise direction) to allow for thelateral flukes 503 and 504 to pull the sacrum and ilium towards eachother, creating compression. The implant 500 may have a minimum(smallest) outer diameter in a range of about 8 mm to about 20 mm (e.g.,about 12 mm to about 18 mm, or any other value or range of valuestherein), and a maximum (largest) outer diameter in a range of about ofabout 12 mm to about 40 mm (e.g., about 15 mm to about 30 mm, or anyother value or range of values therein). The implant may be paired withan exposure device having a hollow barrel with an internal cross-sectionthat corresponds to the outer diameters and cross-sectional shape of theimplant.

The fusion implant 500 may include a cannulated channel or cavity 506that allows for the addition of bone growth-stimulating materials intothe targeted joint. For example, and without limitation, the fusionimplant 500 includes cannulated channel 506 running from a central holein the proximal end of body 501 a distal hole 508 in the body 501. Thecannulated channel 506 may be packed with bone growth-stimulatingmaterials (e.g., autologous bone, allograft, BMP, etc.) to stimulatebone growth across the fusion implant and the joint that may lead tofusion of the sacrum and ilium. The body 501 may have a number offenestrations 507 therein to allow for lateral bone growth through theimplant, which may result in a stable fusion site between the sacrum andilium. Without limiting the invention, the bone growth-stimulatingmaterials may be inserted into the channel 506 through the proximal holein the body 501 after the fusion implant 500 is set into desiredoperative position. In other implementations, the bonegrowth-stimulating materials may be present in the channel 506 prior toinsertion of the fusion implant 500 into the SI joint.

The process of inserting and advancing the fusion implant 500 may beperformed by one or more tools that engage the notches or slots 502. Aninserter (e.g., inserter 147) may be used to initially place the fusionimplant 500 in a desired position between the sacrum and ilium. Withoutlimiting the invention, FIG. 54 shows the fusion implant 500 having aself-distracting bullet nose 509. The bullet nose may have a roundgeometry and/or a tapered rounded profile that is operable to distractthe SI joint with minimal damage to soft and connective tissue in andaround the posterior side of the SI joint. The bullet nose 509 mayfacilitate entry into the sacroiliac joint prior to the lateral flukes503 and 504 being rotated into place in the sacrum and ilium. The slopedbullet nose 509 and the inserter may be subsequently rotated to engagethe lateral flukes 503 and 504 with the bone tissue of the articularsurfaces of the sacrum and ilium. As the fusion implant 500 is rotated,the sacrum and ilium bones may be pulled towards each other and thesacroiliac joint may be compressed and stabilized. Hooking ends 505 maypierce the bone tissue (e.g., cortical and/or cancellous/spongy bonetissue) of the sacrum and ilium. As shown in FIGS. 56-57, but withoutlimitation, the lateral flukes 503 and 504 may be aligned with thenotches 502 for receiving the inserter tool. This alignment may beincluded in order to position the cutting edges in a precise positionwithin the joint (e.g., with the lateral flukes aligned with the planeof the joint between the articular surfaces such that the hooking endsare positioned at the targeted articular surfaces).

As discussed above, and without limiting the invention, the workingchannel through which the implant is passed into the SI joint may havean oblong cross-sectional shape or slots running along its length foraccommodating the lateral flukes of the implant. For example, andwithout limitation, the channel may have a hollow barrel with slots maybe separated by about 180° along the length of the working channel andmay have a shape that can accommodate the shape of the lateral flukes(e.g., a generally rectangular shape that is sufficiently large toaccommodate the shape of the lateral flukes).

FIG. 58 displays the implant 500 in a desired operative position in thesacroiliac joint 102, where lateral fluke 503 is engaged with the ilium200 and lateral fluke 504 is engaged with the sacrum 101. The implantmay create stability and fixation across the joint, compression in thejoint, and bone growth-promoting material can be added to the cannulatedchannel 506 to aid in fusion of the sacrum and ilium at the site of thefusion implant.

In other embodiments of the fusion implant, and without limitation, thefusion implant may have a box-like open body having holes therein forreceiving one or more surgical screws for attaching the fusion implantto the sacrum and/or ilium. Without limiting the invention, FIGS. 59-61show an exemplary embodiment of a fusion implant 600 having a box-likebody 601 having holes 602 a and 602 b in a proximal end thereof forreceiving surgical screws 603 and 604 for engaging with the targetedarticular surfaces of the SI joint and holding the fusion implant 600 inplace within the SI joint. The body 601 may be designed such that acentral plane of the body 601 bisecting the proximal end of the body 601and bisecting screw holes 602 a and 602 b may be roughly aligned withthe plane of the SI joint between the articular surfaces when the fusionimplant is inserted into the SI joint. The box-like geometry of thefusion implant 600 may resist torsional stress applied by movement ofthe SI joint. The implant 600 may have a minimum (smallest) outerdiameter in a range of about 8 mm to about 20 mm (e.g., about 12 mm toabout 18 mm, or any other value or range of values therein), and amaximum (largest) outer diameter in a range of about of about 12 mm toabout 40 mm (e.g., about 15 mm to about 30 mm, or any other value orrange of values therein). The implant may be paired with an exposuredevice having a hollow barrel with an internal cross-section thatcorresponds to the outer diameters and cross-sectional shape of theimplant.

The screw holes 602 a and 602 b may be angled obliquely with respect tothe central plane of the body 601. For example, and without limitation,hole 602 a may run obliquely toward a first lateral side of the centralplane, and hole 602 b may run obliquely toward a second (and opposite)lateral side of the central plane. This arrangement allows the surgicalscrew 603 inserted through screw hole 602 a to engage one of the bonesin the SI joint (e.g., the sacrum) and the surgical screw 604 insertedthrough screw hole 602 b to engage with the other bone in the SI joint(e.g., the ilium).

Without limiting the invention, the surgical screws 603 and 604 may beself-drilling screws that can penetrate the bone tissue (e.g., corticaland/or cancellous/spongy bone tissue) of the articular surface. Thearticular surfaces of the sacrum and/or the ilium may be prepared forthe insertion of the surgical screws by removing cortical tissue at theinsertion point for the screws or pre-drilling holes for the screws; insuch embodiments, self-drilling screws may or may not be utilized. Insome implementations, the surgical screws may be doubled threaded screwsthat create compression of the joints, which may draw the sacrum andilium together as they are advanced into the bone tissue. The screws maybe driven into the bone tissue of the ilium and sacrum by a drivingdevice passed through the working channel positioned over the SI joint,where the driving device has a universal joint or flex shaft (not shown)that allows it to drive the screws into the ilium and sacrum at obliqueangles.

The open body 601 of the implant 600 may have a cavity in which bonegrowth-enhancing materials may be included. The fusion implant 600 mayhave an open design, where there are no sidewalls closing off the cavity606 to the articular surfaces of the sacrum and ilium so that bonegrowth stimulating material that may be placed within the cavity 606 maybe in contact with the articular surfaces of the sacrum and ilium withinthe joint to allow fusion growth across the SI joint. FIG. 61 shows aside view of the fusion implant 600, in which it can be seen that thefusion implant 600 may have a cavity 606 that is completely open on thelateral sides with no sidewalls to obstruct contact between bonegrowth-stimulating materials in the cavity 606 and the articularsurfaces of the sacrum and ilium. As shown in FIG. 60, the fusionimplant 600 may further include openings 607 along the outer wall of thefusion implant to allow further access to the bone growth-stimulatingmaterial in the cavity 606.

The process of inserting and advancing the fusion implant 600 may beperformed by one or more tools that advance the implant through aworking channel, as described herein. An inserter (e.g., inserter 147)may be used to initially place the fusion implant in a desired positionbetween the sacrum and ilium. In some embodiments, and withoutlimitation, the fusion implant may include slots or notches on theproximal end thereof (not shown), which the inserter can engage. Inother embodiments, and without limitation, the inserter may engage thelateral edges of the proximal end of the fusion implant. Once the fusionimplant 600 is placed in the targeted position in the SI joint, thesurgical screws 603 and 604 may be advanced through screw holes 602 aand 602 b, respectively. As the surgical screws 603 and 604 are advancedinto the bone tissue of the sacrum and ilium, the sacrum and ilium bonesmay be pulled towards each other and the sacroiliac joint may becompressed and stabilized. The surgical screws 603 and 604 may piercethe bone tissue (e.g., cortical and/or cancellous/spongy bone tissue) ofthe sacrum and ilium.

As discussed above, and without limiting the invention, the workingchannel through which the implant is passed into the SI joint may havean oblong cross-sectional shape or slots running along its length foraccommodating the width of the fusion implant 600. For example, andwithout limitation, the working channel may have a hollow barrel havingslots may be separated by about 180° along the length of the workingchannel and may have a shape that may accommodate the shape of the bodyof the fusion implant.

FIG. 62 displays the implant 600 in a desired operative position in thesacroiliac joint 102, where surgical screw 603 may be engaged with theilium 200 and surgical screw 604 may be engaged with the sacrum 101. Theimplant may create stability and fixation across the joint, compressionin the joint, and bone growth-promoting material can be added to thecavity 606 to aid in fusion of the sacrum and ilium at the site of thefusion implant.

In other embodiments of the fusion implant, and without limitation, thefusion implant may have a box-like central body having laterallyextending blades for engaging the sacrum and/or ilium. Without limitingthe invention, FIGS. 63-64 show an exemplary embodiments of a fusionimplant 700 having a box-like body 701 having laterally extending blades703 and 704 for engaging with the targeted articular surfaces of the SIjoint and holding the fusion implant 700 in place within the SI joint.The body 701 may be designed such that a central plane of the body 701bisecting the proximal end of the body 701 may be roughly parallel oraligned with the plane of the SI joint between the articular surfaceswhen the fusion implant 700 is inserted into the SI joint. The box-likegeometry of the fusion implant 700 may resist torsional stress appliedby movement of the SI joint. The implant 700 may have a minimum(smallest) outer diameter in a range of about 8 mm to about 20 mm (e.g.,about 12 mm to about 18 mm, or any other value or range of valuestherein), and a maximum (largest) outer diameter in a range of about ofabout 12 mm to about 40 mm (e.g., about 15 mm to about 30 mm, or anyother value or range of values therein). The implant may be paired withan exposure device having a hollow barrel with an internal cross-sectionthat corresponds to the outer diameters and cross-sectional shape of theimplant.

The lateral blades 703 and 704 may be angled obliquely with respect tothe central plane of the body 701. For example, and without limitation,blade 703 may run obliquely toward a first lateral side of the centralplane, and blade 704 may run obliquely toward a second (and opposite)lateral side of the central plane. This arrangement allows the blade 703to engage one of the bones in the SI joint (e.g., the sacrum) and theblade 704 to engage with the other bone in the SI joint (e.g., theilium). The lateral blades may be separately formed or integral to thefusion implant 700. The lateral blades may have an outer edge 705 forengagement with the bone tissue of the sacrum or ilium. The outer edgemay have varying geometry to facilitate entry into and compression ofthe sacrum and ilium. In some implementations, and without limitation,the outer edges of the lateral blades may have a sharp cutting edgewhich can penetrate the bone tissue. In some implementations, andwithout limitation, the outer edges may be serrated (e.g., with one ormore kinds of teeth, such as triangular teeth, hook teeth, crown teeth,etc.). The outer edge may facilitate penetration of the lateral bladesinto the bone tissue (e.g., cortical and/or cancellous/spongy bonetissue) of the articular surfaces of the ilium and sacrum when thefusion implant is advanced into the SI joint. In some implementations,and without limitation, the articular surfaces of the sacrum and/or theilium may be prepared for the insertion of the lateral blades byremoving cortical tissue at the insertion point.

The body 701 of the implant 700 may have a cavity 706 in which bonegrowth-enhancing materials may be included. The fusion implant 700 mayhave an open design, where there are no sidewalls closing off the cavity706 to the articular surfaces of the sacrum and ilium so that bonegrowth stimulating material that may be placed within the cavity 706 maybe in contact with the articular surfaces of the sacrum and ilium withinthe joint to allow fusion growth across the SI joint. As shown in FIG.64, the fusion implant 700 may further include openings 707 along theouter wall of the fusion implant to allow further access to the bonegrowth-stimulating material in the cavity 706. The fusion implant 700may include a central hole 708 in the proximal end of the body 701. Thecentral hole 708 may allow for access into the cavity 706, allowing thebone growth-stimulating materials to be inserted into the cavity 706either before or after the fusion implant 700 is set into desiredoperative position in the SI joint. In some implementations, the bonegrowth-stimulating materials may be present in the cavity 706 prior toinsertion of the fusion implant 700 into the SI joint. The design offusion implant 700 (and other related embodiments) allows for bone graftto be placed pre-operatively as the cavity 706 is not obscured by thelateral blades (bone anchoring mechanism).

The process of inserting and advancing the fusion implant 700 may beperformed by one or more tools that advance the implant through aworking channel, as described herein. An inserter (e.g., inserter 147)may be used to initially place the fusion implant in a desired positionbetween the sacrum and ilium. In some embodiments, and withoutlimitation, the fusion implant may include slots or notches on theproximal end thereof (not shown), which the inserter can engage. Inother embodiments, and without limitation, the inserter may engage thelateral edges of the proximal end of the fusion implant. The fusionimplant 700 may be drive into place in the targeted position in the SIjoint by the inserter. As the fusion implant 700 is advanced into the SIjoint, the lateral blades 703 and 704 are driven into and penetrate thebone tissue of the sacrum and ilium, and the blades 703 and 704 may actto draw in the sacrum and ilium bones and the sacroiliac joint may becompressed and stabilized. The lateral blades 703 and 704 may pierce thebone tissue (e.g., cortical and/or cancellous/spongy bone tissue) of thesacrum and ilium as the fusion implant is driven into the SI joint. Inother implementations, and without limitation, the inserter may be usedto place the fusion implant 700 at the SI joint, and subsequently animpactor or other driving tool may be used to drive the fusion implant700 into the bone tissue and into position in the SI joint.

As discussed above, and without limiting the invention, the workingchannel through which the implant is passed into the SI joint may have ahollow barrel having an oblong interior cross-sectional shape or slotsrunning along its length for accommodating the width of the fusionimplant 700 and the lateral blades 703 and 704. For example, and withoutlimitation, a first set of slots may be separated by about 180° alongthe length of the working channel and may have a shape that iscomplementary to or large enough accommodate the shape of the fusionimplant, and a second set of slots may be separated by about 180° alongthe length of the working channel and may have a shape may accommodatethe shape of the lateral blades.

FIGS. 65-66 show a fusion implant 700 a that is similar to implant 700in shape, size, and function, but the blades 703 a and 703 b of implant700 a are detachable from the implant. As shown in FIG. 65, the lateralblades 703 a and 703 b are inserted into slots 710 a and 710 b in thedistal portion of the body 701 a, respectively. This fusion implantembodiment allows for the body 701 a to be inserted into the SI jointprior to the insertion of the blades 703 a and 703 b into the body 701a. This may allow the implant 700 a to be inserted into the SI joint andthe blades to be subsequently inserted into the slots 710 a and 710 band engaged with the bone tissue of the ilium and sacrum without theneed for a specially shaped (e.g., oblong or slotted) working channel.The blades 703 a and 703 b may be passed through the working channel andinto slots 710 a and 710 b after the body 701 a has been positioned inthe SI joint. An inserter and/or impactor or other tools may be used toinsert the blades 703 a and 703 b into the slots 710 a and 710 b andinto the bone tissue of the ilium and sacrum.

As shown in FIG. 66, the blades of implant 700 a may include pressureclips 711 that engage with slots 710 a and 710 b when the blades areinserted into the slots. The pressure clips may lock the blades into theslots to help stabilize the fusion implant.

FIG. 67 displays the implant 700 (or implant 700 a) in a desiredoperative position in the sacroiliac joint 102, where lateral blade 703is engaged with the ilium 200 and lateral blade 704 is engaged with thesacrum 101. The implant may create stability and fixation across thejoint, compression in the joint, and bone growth-promoting material canbe added to the cavity 706 to aid in fusion of the sacrum and ilium atthe site of the fusion implant.

In other embodiments of the fusion implant, and without limitation, thefusion implant may have a box-like central body having a rotatablecentral axle with lateral flukes thereon for engaging the sacrum and/orilium as the central axle is rotated. Without limiting the invention,FIGS. 68-69 show an exemplary embodiment of a fusion implant 800 havinga box-like open body 801 having a central axel 805 to which two flukes803 and 804 are attached for engaging with the targeted articularsurfaces of the SI joint and holding the fusion implant 800 in placewithin the SI joint. The flukes 803 and 804 may engage with thearticular surfaces of the sacrum and ilium, respectively, when thecentral axis is rotated. The body 801 may be designed such that acentral plane of the body 801 bisecting the proximal end of the body 801may be roughly parallel to or aligned with the plane of the SI jointbetween the articular surfaces when the fusion implant 800 is insertedinto the SI joint. The box-like geometry of the fusion implant 800 mayresist torsional stress applied by movement of the SI joint. The implant800 may have a minimum (smallest) outer diameter in a range of about 8mm to about 20 mm (e.g., about 12 mm to about 18 mm, or any other valueor range of values therein), and a maximum (largest) outer diameter in arange of about of about 12 mm to about 40 mm (e.g., about 15 mm to about30 mm, or any other value or range of values therein). The implant maybe paired with an exposure device having a hollow barrel with aninternal cross-section that corresponds to the outer diameters andcross-sectional shape of the implant.

Without limiting the invention, the flukes 803 and 804 may extend outlaterally from central rotating axis 805 at about 180° from each other.This arrangement allows the fluke 803 to engage one of the bones in theSI joint (e.g., the sacrum) and the fluke 804 to engage with the otherbone in the SI joint (e.g., the ilium) as the central axle 805 isrotated. In other implementations, and without limitation, the flukesmay have other relative positions on the central axle. In still otherimplementations, and without limitation, the fusion implant may havemore than two flukes attached to the central axis that may be arrangedin various positions on the central rotating axle. Without limiting theinvention, the curvature of all of the flukes extending from the centralaxle may be oriented in either a clockwise or counterclockwise fashionwhen viewing the fusion implant from the proximal end of the body (e.g.,like the perspective of FIG. 69). The consistent orientation of all ofthe flukes allows all of the hooks to engage (hook into) the tissue inthe SI joint as the central axle is rotated. In other implementations,and without limitation, one or more of the flukes on the central axlemay be obliquely oriented, which may provide additional bite andpurchase into the bone tissue. The hooking edge of the hooks may havevarying geometry to facilitate entry into and compression of the sacrumand ilium. In some implementations, and without limitation, the hookingedges of the flukes may have a sharp cutting edge which can penetratethe bone tissue. In some implementations, and without limitation, thehooking edges may be serrated (e.g., with one or more kinds of teeth,such as triangular teeth, hook teeth, crown teeth, etc.). The hookingedges may facilitate penetration of the flukes into the bone tissue(e.g., cortical and/or cancellous/spongy bone tissue) of the articularsurfaces of the ilium and sacrum when the central axle is rotated. Insome implementations, and without limitation, the articular surfaces ofthe sacrum and/or the ilium may be prepared for the insertion of thesurgical screws by removing cortical tissue at the insertion point.

The body 801 of the implant 800 may have a cavity 806 through which thecentral axle 805 passes. The central axle may rotatably attach to boththe proximal and distal ends of the body 801, such that the central axle805 may be rotated once the fusion implant is inserted into the SIjoint. The central axle 805 may be rotatable in either the clockwiseand/or the counterclockwise direction (e.g., from the perspective ofFIG. 69). In some implementations, and without limitation, the centralaxle 805 may be rotatable in only one direction, that being thedirection that allows the hooks to bite into the bone tissue in the SIjoint. The one-directional implementation may prevent the hooks fromrotating and slipping out of the bone tissue, once they have beenrotated and inserted into the bone tissue in the SI joint.

The cavity 806 may have an open design into which bone growth-enhancingmaterials may be inserted. The body 801 may have no sidewalls closingoff the cavity 806 to the articular surfaces of the sacrum and ilium sothat bone growth stimulating material that may be placed within thecavity 806 may be in contact with the articular surfaces of the sacrumand ilium within the joint to allow fusion growth across the SI joint.As shown in FIG. 68, the fusion implant 800 may further include openings807 along the outer wall of the fusion implant 800 to allow furtheraccess to the bone growth-stimulating material in the cavity 806.

The process of inserting and advancing the fusion implant 800 may beperformed by one or more tools that advance the implant through aworking channel, as described herein. An inserter (e.g., inserter 147)may be used to initially place the fusion implant in a desired positionbetween the sacrum and ilium. In some embodiments, and withoutlimitation, the fusion implant may include slots or notches on theproximal end thereof (not shown), which the inserter can engage. Inother embodiments, and without limitation, the inserter may engage thelateral edges of the proximal end of the fusion implant. Subsequently, adriving tool may be engaged with a central hole 802 in the proximal endof the body 801, which may be “keyed” with teeth or other structuresthat can be engaged by the driving tool. The driving tool may beoperable to rotate the central axle 805 once it is engaged with thecentral hole 802, thereby driving the flukes 803 and 804 into the bonetissue in the articular surfaces of the sacrum and ilium.

In some embodiments, and without limitation, the inserter may have ahead that has a complementary shape to the central hole 802, allowingthe inserter to engage the with the central hole 802 prior to insertion.The ring structure around the central hole 802 may be connected with orintegral to the central axle 805, allowing central axle to be rotated bythe inserter. For example, and without limitation, the inserter can beused to insert the fusion implant into the SI joint, and then the headof the inserter may be rotated in order to rotate the central axle ofthe fusion implant, thereby engaging the hooks with the bone tissue inthe articular surfaces of the sacrum and ilium.

As discussed above, and without limiting the invention, the workingchannel through which the implant is passed into the SI joint may have ahollow barrel having an oblong internal cross-section or slots runningalong its length for accommodating the width of the fusion implant 800and the lateral flukes 803 and 804.

The central hole 802 may also allow for access into the cavity 806, suchthat bone growth-stimulating materials may be inserted into the cavity806 after the fusion implant 800 is set into desired operative positionin the SI joint. In some implementations, and without limitation, thebone growth-stimulating materials may be present in the cavity 806 priorto insertion of the fusion implant 800 into the SI joint. The design offusion implant 800 (and other related embodiments) allows for bone graftto be placed pre-operatively as the cavity 806 is not obscured by thecentral axle and hooks (bone anchoring mechanism).

In some embodiments, and without limitation, the fusion implant may havea shape and features like the implant 151 shown in FIGS. 39 and 126-129.As an example, and without limiting the invention, the implant may be abone graft as shown in FIGS. 126-129. The implant 151 may besubstantially rectangular, having ribbing 153 on opposing sides tocreate a surface for catching or gripping with the SI joint when it isinserted. The implant 151 may also have a tapered proximal end to beinserted into the SI joint to act as a wedge, facilitating insertion.The implant 151 may also have slots 152 for receiving forceps of aninserter, and transverse holes to allow bone tissue to grow through theimplant and incorporate the implant into the native bone tissue, therebyfusing the SI joint.

FIGS. 71-91 displays the implant in a desired operative position in thesacroiliac joint 102, where the implant is engaged with the ilium 200and the sacrum 101. The implant may create stability and fixation acrossthe joint, compression in the joint, and bone growth-promoting materialcan be added to the cavity 806 to aid in fusion of the sacrum and iliumat the site of the fusion implant.

Surgical Methods

In some embodiments, the methods of the present invention substantiallyfuse the SI joint, such that movement in the joint is minimized orsubstantially eliminated, thereby diminishing or substantiallyeliminating the patient's pain and discomfort. More specifically, animproved, combined approach for both mechanical holding and surgicalfusion through a novel exposure device is described herein.Specifically, with respect to some embodiments, an approach is describedto address the SI joint through a posterior approach. In someembodiments, and without limitation, the surgical fusion of the sacrumand an ilium may be accomplished with a posteriorly inserted fusionimplant device alone. In other embodiments, and without limitation,surgical fusion may be accomplished with the delivery of both (1) afusion implant device into the SI joint, and (2) a separate fixationdevice which can be in the form of a screw, or the like. The fusion maybe delivered to the SI joint, placed between the sacrum and ilium, whilethe fixation device may be delivered through the iliac wing, near theiliac crest, into the sacrum while not entering or passing through theSI joint.

In some embodiments, and without limitation, the method may involve theposterior insertion of a fusion implant, including the steps of creatingan incision proximal to the patient's SI joint, dilating the incision,engaging a novel exposure device as described herein with the incision,creating a void in the SI joint, and inserting the fusion implant intothe void such that it engages with the articular surfaces of the sacrumand ilium.

Some embodiments, without limitation, include some or all of thefollowing steps, preparing the patient for surgery (e.g., positioningthe patient in a prone position to provide the surgeon access to the SIjoint, general or local anesthesia, and the like), locating the SI jointand an incision point for access to the SI joint (e.g., by blunt fingerpalpation), insertion of a pin or wire to create an incision, insertionof a dilator over the pin and impacting the dilator to dilate theincision to a width through which instruments may be passed, inserting aworking channel of a novel exposure device over the dilator, securingthe working channel in position with fixing pins, removing the dilator,inserting a drill bit apparatus through the working channel, using thedrill bit apparatus in the working channel to displace bone in the SIjoint thereby creating a void, removing the drill bit apparatus, loadinga fusion implant onto an inserter and inserting the fusion implant andinserter into the working channel until the implant is positionedproximal to the void in the patient's SI joint, inserting an impactorinto the first working channel and applying force to displace theimplant into the void in the patient's SI joint, removing allinstruments, and closing the incision.

In some embodiments, and without limitation, the method may involve theposterior insertion a fusion implant and the insertion a separatefixation device through the ilium and sacrum, including the steps ofcreating an incision proximal to the patient's SI joint, creating anincision over iliac wing, dilating the incisions, engaging a novelexposure device as described herein with both incisions, creating a voidin the SI joint, inserting a fusion implant into the void, drilling ahole through the ilium and the S1 vertebra of the sacrum, and insertinga joint fusing device in the ilium and sacrum. The fixation device maybe inserted through the iliac wing, near the iliac crest, into thesacrum while not entering or passing through the SI joint.

Other embodiments, without limitation, include some or all of thefollowing steps, preparing the patient for surgery (e.g., positioningthe patient in a prone position to provide the surgeon access to the SIjoint, general or local anesthesia, and the like), making a smallincision over the top of the iliac wing from a posterior approach,locating the SI joint and an incision point for access to the SI joint(e.g., by blunt finger palpation), insertion of a pin or wire to createan incision, insertion of a dilator over the pin and impacting thedilator to dilate the incision to a width through which instruments maybe passed, inserting a first working channel of a double-barreled,double-angled exposure device over the dilator and inserting a secondworking channel of said exposure device in the incision over the iliacwing, securing the first and second working channels in position withfixing pins, removing the dilator, inserting a drill bit apparatusthrough each of the first and second work channels, using the drill bitapparatus in the first working channel to displace bone in the SI jointthereby creating a void, using the drill bit apparatus (or a seconddrill bit apparatus) in the second working channel to drill a hole inthe iliac crest and the S1 vertebra of the sacrum, removing the drillbit apparatus, loading an implant (e.g., a graft) onto an inserter andinserting the implant and inserter into the first working channel untilthe implant is positioned proximal to the void in the patient's SIjoint, inserting an impactor into the first working channel and applyingforce to displace the implant into the void in the patient's SI joint,inserting a joint fusion device coupled to a fusion device inserter intothe second working channel and implanting said joint fusion device inthe hole in the iliac crest and the sacrum, removing all instruments,and closing the incisions.

Some embodiments include the use of embodiments of the tools or toolsets of the present invention, as described above. Other embodiments ofthe methods of the present invention are performed without using thetools of the present invention. The methods of the present invention maybe performed in addition to or in conjunction with one or more of theknown methods. Embodiments of the methods of the present invention (andtools of the present invention) are now further described with referenceto the Figures. Although the methods are described with respect to theuse of certain tools, other tools with different structures may be usedand still be within the scope of the present invention.

FIGS. 72-99 illustrate a surgical procedure for fusing an SI joint withboth a fusion implant inserted in the SI joint and a joint fixationdevice (e.g., a bone screw). The procedure includes positioning apatient in the prone position and administering either a local orgeneral anesthetic. Blunt finger palpation may be used to locate thepatient's iliac wing and the SI joint. As shown in FIG. 72, the SI joint102 is located between the iliac wing 100 and the sacrum 101 at the baseof the pelvis. The SI joint is fully enclosed between the iliac wing 100and the sacrum 101 and occluded for direct visualization by the iliacwing 100. Additionally, the iliac crest 200, the posterior iliac spines,and the pedicle 104 of vertebrae S1 can be observed in this view. Theiliac crest 200 may provide a posterior landmark for the entry point ofthe exposure device of the present invention at the posterior iliaccrest, and can be palpated to find the general location of the SI joint.Alternatively, suitable locations for an incision may be determined byimaging methods (e.g., x-ray), or any other suitable method.

As illustrated in FIG. 73-74, and without limitation, a joint probe 112may be used to identify the insertion area on the posterior side of theSI joint. The area of the SI joint may be probed until the roundedgeometry of the joint probe 112 finds or drops into the proper positionin the SI joint, where an incision may be properly made. Subsequently, aguide pin 114 may be inserted through a central channel in the jointprobe 112 and into the patient to create an incision in the SI joint, asillustrated in FIG. 70. Alternatively, the incision may be made by anysuitable method, including scalpel or other cutting or dissection tool.The incision may be made proximal to the patient's SI joint, allowingthe joint to be accessed by the exposure device. The guide pin 114 maybe advanced until its proximal end is in contact with the SI joint or atleast partially within SI joint.

As illustrated in FIGS. 76-79, and without limitation, a dilator may beused to dilate the incision. As an example, dilator 116 may be slottedover guide pin 114 through a central channel running the length of thedilator 116. The proximal end of the dilator 116 may be slotted over theguide pin 114, and dilator 116 may then be advanced to or near the SIjoint through the incision. As dilator 116 enters the incision, thetapered end 118 pushes the patient's flesh and tissue aside, therebydilating incision to accommodate an exposure device as described herein.A joint cutting assembly that includes the dilator 116 and a T-handle120 engaged with a distal end of the dilator 116 may be used to furtherdrive the dilator 116 into the incision to a desired depth tosufficiently expose the SI joint. Alternatively, an impactor (not shown)may be used to further drive the dilator 116 into the incision to adesired depth.

FIG. 76 illustrates the placement of the exposure device 137 over thedilator 116. The exposure device 137 is advanced over dilator 116 andinto incision. Dilator 116 enters the hollow barrel of exposure tool atthe distal end of the working channel 239. The working channel 239 ofthe exposure tool has distal end 142 that may have a round geometryand/or a tapered rounded profile that is operable to distract the SIjoint with minimal damage to soft and connective tissue in and aroundthe posterior side of the SI joint. The working channel may includetangs extending from distal end 142 for engaging the SI joint betweenthe sacrum and ilium. The tangs may align between the articular surfacesand help to position and stabilize the working channel. It is to beappreciated that the working channel may have other perimeter shapessuch as oval, to accommodate the shape of some fusion implants. Itshould be understood that the working channel may have other shapes aswell (e.g., triangular, polygonal [pentagonal, hexagonal, etc.],Reuleaux shapes, and other applicable shapes). The exposure device mayalso further dilate incision. The exposure device is advanced toward SIjoint through incision until proximal end 142 is in contact with the SIjoint or proximal to the SI joint and in contact with the sacrum and/orilium. In such embodiments, dilator 116 functions to guide the proximalend 142 to the patient's SI joint.

FIGS. 78-81 illustrate a process of stabilizing the exposure device 137within incision. As depicted, the exposure device is stabilized usingfixing pins 126, slotted through fixing pin holes or slots 139 on sidesof the working channel 239. Fixing pins 126 may have any suitablestructure that permits them to stabilize the exposure device 137. Insome embodiments, and without limitation, stabilizing pins 126 canpenetrate the skin and/or flesh and tissue of a human. It is to beappreciated that any suitable method of stabilizing exposure device maybe used. Dilator 116 and guide pin 115 may be removed from the workingchannel either before or after the fixing pins 126 are inserted. Inother embodiments, and without limitation, the exposure device may bestabilized by attachment to a surgical or stabilizing arm to hold theexposure device in a static and stable position.

A guide pin 115 may be inserted into the incision through the workingchannel 239, either through the dilator before it is removed, or througha guide sleeve that may be used to insert the guide pin 115 and then maybe removed from the working channel 239.

FIGS. 82-83 illustrate insertion of drill bit apparatus 122 into theincisions through the working channel 239 of the exposure device 137.The drill bit may be connected to a power drill configured for medicalprocedures. The drill bit apparatus 122 may have cylindrical outer wallsthat allow the drill bit apparatus to freely spin with the hollow barrelof the working channel 239. The cylindrical outer wall may comprise alow-friction material that facilitates smooth spinning of the drillwithin the hollow barrel of the working channel. The proximal end of thedrill bit apparatus 122 may be inserted into the working channel 239 andmay be advanced to a predetermined point. In some examples, and withoutlimitation, the proximal end of drill bit apparatus 122 does not extendpast the proximal end of the working channel 239 when fully inserted.Preferably, drill bit apparatus 122 may be configured such that it willinteract with the working channel 239 only in an orientation thatensures proper positioning of drill bit apparatus 122 relative to the SIjoint. For example, and without limitation, the drill bit apparatus mayfit snugly into the hollow barrel to avoid any axial deviations, but maystill be able to spin freely and at a rapid rotational speed withoutcausing excessive friction or causing significant extraneous or unwantedmotion. In other embodiments, and without limitation, the drill bit mayhave an outer stationary housing that is complementary to and fitssnugly within the hollow barrel of the working channel, and the rotatingportion of the bit may be within the outer stationary housing and can berotated while the stationary outer housing is statically engaged withthe hollow barrel of the working channel.

In some implementations, and without limitation, the drill bit in thedrill bit apparatus 122 may be advanced into the working channel 239toward SI joint to a predetermined depth. This may be accomplished by anarrestor system in the drill that only allows a particular depth ofinsertion or by any other suitable method. The drill bit in the workingchannel 239 may be positioned such that when activated it will create avoid in the patient's SI joint by displacing portions of sacrum andilium. In such examples, the drill bit may be configured such that itwill contact the patient's SI joint at a desired portion of the jointand, once activated, will create a void of a desired depth. The void maybe configured to receive a fusion implant as described herein or otherjoint repairing appliance or bone graft for fusing the SI joint. Otherjoint repairing appliances or apparatus may include a polyether etherketone (PEEK) implant, a titanium implant, etc. As an example andwithout limiting the invention, the implant may be a fusion implant likeone of those shown in FIGS. 49-70.

As shown in FIGS. 84-93, several implements may be inserted through theworking channel 239 into the void in the SI joint to prepare the voidfor receiving a fusion implant. For instance, a box chisel 131 and/or arasp 132 may be inserted into the void through the working channel 239to expand and clear tissue from the void to facilitate a clean andefficient insertion of the fusion implant into the void (see, e.g.,FIGS. 84-86). As shown in FIGS. 88-89, an impactor 136 may also be usedto deepen or spread the void.

FIGS. 39 and 90 illustrate the use of a fusion implant inserter 147 toinsert a fusion implant into the void in the SI joint. The inserter 147may be inserted into the working channel 239 of the exposure device 137once a void has been formed in the SI joint. For example, and withoutlimitation, prior to insertion, the fusion implant is grasped by forcepsof the inserter 147, which may engage with grooves along sides of thefusion implant. In other examples, and without limitation, the insertermay have a head that is threaded, keyed, or otherwise structured suchthat it is complementary to a hole in the proximal end of the fusionimplant (e.g., the proximal hole in fusion implant 700 or 800). Onceengaged with the fusion implant, the inserter 147 may be inserted intothe working channel and may be advanced until it meets resistance at thevoid. The inserter 147 may be operable to then release the fusionimplant, leaving it in the void. In some examples, the inserter 147 mayhave a mechanism for grasping and releasing the fusion implant (e.g.,arms 149 may be operable to clamp and release the fusion implant),providing an efficient means of depositing the fusion implant in thevoid.

In some implementations, and without limitation, the fusion implant mayrequire that one or more elements thereof be rotated in order for thefusion implant to engage with the bone tissue in the SI joint (e.g.,fusion implants 400,400 a, 500, 800, and other related embodiments). Insome implementations, and without limitation, the inserter may have armsthereon for engaging slots or notches in the proximal end of the fusionimplant and may be capable of rotating the fusion implant (e.g., fusionimplants 400, 400 a, 500, and related embodiments) once it is placed inthe SI joint. In such implementations, the inserter may have distalrotatable member that is capable of rotating independently of shaft andhandle of the inserter, allowing the surgeon to use the inserter toplace the fusion implant into the void in the proper orientation withoutunwanted rotation and then deliberately rotate the fusion implant andengage it with the articular surfaces. In other implementations, andwithout limitation, the inserter may include a distal head that may beoperable to engage a hole in the proximal surface of the fusion implant,which may be threaded or machined (e.g., to have gear teeth, notches,angular sides [e.g., a square shape, etc.] or other features) in amanner to allow an interlocking fit with the distal head of theinserter. In such implementations, the distal head may be operable torotate the fusion implant once it is placed in the void in the SI joint.In other implementations, and without limitation, a tool separate fromthe inserter may be used to rotate the fusion implant once it is inplace within the SI joint. For example, and without limitation, a driverhaving a distal head operable to engage the fusion implant may be passedthrough the working channel and engage with the fusion implant, andsubsequently rotate the fusion implant.

An impactor 236 may be used to exert force on the fusion implant as itis in the void, in order to drive the fusion implant securely into thevoid, as shown in FIG. 91. The impactor may be utilized to drive thefusion implant into the bone tissue of the articular surfaces of the SIjoint, particularly in implementations that utilize a fusion implanthaving lateral blades (e.g., fusion implant 700 and relatedembodiments). The fusion implant may thereby be properly inserted intothe void. Though, the impactor may be used in other implementations aswell, for example, to drive the fusion implant deeper into the voidprior to rotating the fusion implant (e.g., fusion implants 400, 400 a,500, and related embodiments), or prior to driving screws of the fusionimplant into the articular surfaces of the SI joint (e.g., fusionimplant 600 and related embodiments). Additionally, the impactor 236 maybe used to add additional therapeutic materials, such as bonemorphogenetic proteins (BMP), demineralized bone matrix (DBM), stemcells, and other materials, to the void to improve recovery and growthof the bone in the SI joint.

Subsequently, the exposure device may be removed from the patient. Also,the fixing pins 126 may be removed from both incisions. The tissues inthe incisions may then be sutured, to facilitate healing.

In some embodiments of the present invention, and without limitation,surgical fusion may be accomplished with the delivery of both (1) afusion implant device into the SI joint, and (2) a separate fixationdevice which can be in the form of a screw, or the like. The fusion maybe delivered to the SI joint, placed between the sacrum and ilium, whilethe fixation device may be delivered through the iliac wing, near theiliac crest, into the sacrum while not entering or passing through theSI joint. In such embodiments, the steps of locating the SI joint andmaking an incision over the SI joint may be the same or similar to thesteps described above and as shown in FIGS. 71-77.

FIGS. 92-114 illustrate additional steps of a surgical procedure forfusing an SI joint with both a fusion implant inserted in the SI jointand a joint fixation device (e.g., a bone screw) fixing the ilium andsacrum together. The procedure may include making an incision over theiliac wing near the iliac crest for the insertion of a second workingchannel of a double-barreled, double-angled exposure device. A dilatormay be used to dilate an incision formed over the SI joint, aspreviously described. As an example, and without limitation, FIGS. 92-93show dilator 116 may be slotted over a guide pin 114 through a centralchannel running the length of the dilator 116. The proximal end of thedilator 116 may be slotted over the guide pin 114, and dilator 116 maythen be advanced to or near the SI joint through incision. As dilator116 enters the incision, the tapered end 118 pushes the patient's fleshand tissue aside, thereby dilating incision to accommodate exposuredevice. A joint cutting assembly that includes the dilator 116 and aT-handle 120 engaged with a distal end of the dilator 116 may be used tofurther drive the dilator 116 into the incision to a desired depth tosufficiently expose the SI joint. Alternatively, an impactor (not shown)may be used to further drive the dilator 116 into the incision to adesired depth.

FIGS. 94-95 illustrate the placement of the double-barreled,double-angled exposure device over the dilator 116. The exposure deviceis advanced over dilator 116 and into incision. Dilator 116 enters thehollow barrel of exposure tool at the distal end of the first workingchannel 239. Without limiting the invention, the first working channel239 of the exposure tool has proximal end 142 that may have a roundgeometry and/or a tapered rounded profile that is operable to distractthe SI joint with minimal damage to soft and connective tissue in andaround the posterior side of the SI joint. It is to be appreciated thatthe working channel may have other perimeter shapes circular, oval,triangular, polygonal (pentagonal, hexagonal, etc.), Reuleaux shapes,and other applicable shapes. The exposure device may also further dilateincision. The exposure device is advanced toward SI joint throughincision until proximal end 142 is in contact with the SI joint orproximal to the SI joint and in contact with the sacrum and/or ilium. Insuch embodiments, dilator 116 functions to guide the proximal end 142 tothe patient's SI joint.

The exposure device may be configured such that when the first workingchannel 239 of the exposure device is established in position in or nearthe SI joint the second working channel 240 is oriented over the iliacwing near the iliac crest (the location of the incision) and in anorientation that will allow the second working channel to guide a drillbit through the ilium and sacrum (e.g., the S1 vertebra) withouttraversing the SI joint (i.e., without causing damage to the SI joint).The relative position of the first and second working channels of thedouble-barreled, double-angled exposure device accommodates the contourof the pelvis between the ilium and the SI joint such that said firstworking channel can be engaged with a posterior side of the SI joint andsaid second working channel can be engaged with a posterior portion ofthe iliac wing at an angle that is aligns a longitudinal axis of thesecond working channel anterior to the SI joint.

FIGS. 96-99 illustrate a process of stabilizing the exposure devicewithin incision. As depicted, the exposure device is stabilized usingfixing pins 126, slotted through fixing pin holes or slots 139 on sidesof the first and second working channels 239 and 240. Fixing pins 126may have any suitable structure that permits them to stabilize theexposure device. In some embodiments, stabilizing pins 126 can penetratethe skin and/or flesh and tissue of a human. It is to be appreciatedthat any suitable method of stabilizing exposure device may be used.Dilator 116 and guide pin 115 may be removed from the first workingchannel either before or after the fixing pins 126 are inserted.

Guide pins 115 may be inserted into the incision through the first andsecond working channels 239 and 240, either through the dilator beforeit is removed, or through guide sleeves that may be used to insert theguide pins 115 and that may then be removed from the first and secondworking channels 239 and 240. FIGS. 100-102 provide views of exemplaryguide pin placement for the double-barreled exposure device frommultiple perspectives. FIGS. 103-104 provide views of exemplaryplacement of the double-barreled exposure device from multipleperspectives.

FIGS. 105-106 illustrate insertion of drill bit apparatus 122 into theincisions through the first and second working channels 239 and 240 ofthe exposure device. The drill bit may be connected to a power drillconfigured for medical procedures. The drill bit apparatus 122 may havecylindrical outer walls that allow the drill bit apparatus to freelyspin with the hollow barrel of the first and second working channels 239and 240. The cylindrical outer wall may comprise a low-friction materialthat facilitates smooth spinning of the drill within the hollow barrelsof the first and second working channels. The proximal ends of the drillbit apparatus 122 may be inserted into the first and second workingchannels 239 and 240 and may be advanced to a predetermined point. Insome examples, the proximal ends of drill bit apparatus 122 do notextend past the proximal end of the first and second working channels239 and 240 when fully inserted. Preferably, drill bit apparatus 122 areconfigured such that it will interact with the first and second workingchannels 239 and 240 only in an orientation that ensures properpositioning of drill bit apparatus 122 relative to the SI joint and theilium. For example, the drill bit apparatus may fit snugly into thehollow barrel to avoid any axial deviations, but may still be able tospin freely and at a rapid rotational speed without causing excessivefriction or causing significant extraneous or unwanted motion. In otherembodiments, and without limitation, the drill bit may have an outerstationary housing that is complementary to and fits snugly within thehollow barrel of the working channel, and the rotating portion of thebit may be within the outer stationary housing and can be rotated whilethe stationary outer housing is statically engaged with the hollowbarrel of the working channel.

The drill bits in the drill bit apparatus 122 may be advanced intochannel the first and second working channels 239 and 240. With regardto the drill in the first working channel 239, the drill bit is advancedtoward SI joint to a predetermined depth. This may be accomplished by anarrestor system in the drill that only allows a particular depth ofinsertion or by any other suitable method. The drill bit in the firstworking channels 239 may be positioned such that when activated it maycreate a void in the patient's SI joint by displacing portions of sacrumand ilium. In such examples, the drill bit may be configured such thatit will contact the patient's SI joint at a desired portion of the jointand, once activated, will create a void of a desired depth.

The void may be configured to receive a fusion implant as describedherein or other joint repairing appliance or apparatus for fusing the SIjoint. Other joint repairing appliances apparatus may include apolyether ether ketone (PEEK) implant, a titanium implant, etc. As anexample and without limiting the invention, the implant may be a fusionimplant like one of those shown in FIGS. 49-70. The fusion implant mayalso have slots for receiving forceps of an inserter tool or a hole orrecess in a proximal end of the fusion implant for receiving an insertertool, and transverse holes to allow bone tissue to grow through theimplant, and incorporate the implant into the native bone tissue,thereby fusing the SI joint.

The drill bit in the second working channels 239 may be positioned suchthat when activated it will drill a hole through the iliac wing of thepatient near the iliac crest and through the sacrum (e.g., the S1vertebra). The drill bit may have sufficient length to reach the S1vertebra from the iliac wing position of the second working channel. Therelative angled position of the first and second working channels 239and 240 of the exposure device positions the second working channel suchthat the drill bit can be advanced through to the S1 vertebra withouttraversing (passing through) the SI joint, thereby avoiding any damageto the SI joint tissues (e.g., the ligaments).

As shown in FIGS. 107-112, several implements may be inserted throughthe first working channel 239 into the void in the SI joint to preparethe void for receiving a fusion implant. For instance, and withoutlimitation, a box chisel 131 and or a rasp 132 may be inserted into thevoid through the first working channel 239 to expand and clear tissuefrom the void to facilitate a clean and efficient insertion of thefusion implant into the void. An impactor 136 may also be used to deepenor spread the void.

FIGS. 39 and 113 illustrate the use of a fusion implant inserter 147 toinsert a fusion implant (e.g., as described above and shown in FIGS.49-70) into the void in the SI joint. The inserter 147 may be insertedinto the first working channel 239 of the exposure device. Prior toinsertion, the fusion implant may be grasped by the forceps of theinserter 147, which may engage with grooves or recesses on the fusionimplant. In other implementations, and without limitation, the fusionimplant may have a hole or recess in a proximal end of the fusionimplant for receiving an inserter tool, and the inserter tool may have ahead or extension that fits within the hole or recess. The inserter 147and the fusion implant may be inserted together into the first workingchannel and may be advanced until it meets resistance at the void. Theinserter 147 may then release the fusion implant, leaving it in thevoid. In some examples, the inserter 147 may have a mechanism forgrasping and releasing the fusion implant, providing an efficient meansof depositing the fusion implant in the void.

Subsequently, an impactor 236 may be used to exert force on the fusionimplant in the void, in order to drive fusion implant securely into thevoid, as shown in FIG. 114. The fusion implant may thereby be properlyinserted into the void. Additionally, the impactor 236 may be used toadd therapeutic materials, such as bone morphogenetic proteins (BMP),demineralized bone matrix (DBM), stem cells, and other materials, to thevoid to improve recovery and growth of the bone in the SI joint.

A joint fixation device (e.g., a compression screw) may be inserted intothe iliac wing and the sacrum (the S1 vertebra) through the secondworking channel as the double-barreled exposure device is secured to theSI joint and the ilium. A fixation device 158 may be inserted at angleinto the ilium and the sacrum that compresses the SI joint, therebycompressing the fusion implant within the SI joint. However, in otherembodiments, the angle of the hole drilled in the ilium and sacrum in anorientation that distracts the SI joint, providing room in the SI jointfor bone tissue grow around the fusion implant. In further embodiments,the structure of the joint fixation device 158 may be configured tocreate distraction in the SI joint.

The joint fixation device 158 may be inserted into the second workingchannel along with a fixation implant driver 125 engaged therewith. Inthe case of a screw, the screw 158 may be advanced into the hole drilledthrough the ilium and the sacrum manually with a specialized driver 125.Alternatively, the screw or other fusion device can be installed by anautomated process. Without limiting the invention, FIGS. 115-116 show anexemplary fixation device 158 and an exemplary fusion implant 151positioned in the pelvis from posterior and superior views,respectively. The fusion implant 151 sits in the SI joint 102 betweenthe articular surfaces of the sacrum 101 and the iliac wing 100. Thefixation device 158 passes through the iliac wing 100 and into the bodyof S1 of the sacrum 101 without traversing (passing through) the SIjoint 102.

Once the fusion implant 151 and the fixation device 158 are implanted intheir proper positions, the fixation implant insertion implant device125 and the double-barreled exposure device may be removed from thepatient. Also, the fixing pins 126 may be removed and the exposuredevice may be removed from both incisions. The tissues in the incisionsmay then be sutured, to facilitate healing.

In some embodiments, and without limitation, the working channels mayhave different structures and orientations. Without limiting theinvention, FIGS. 117-120 illustrate further embodiments of theinvention. In FIG. 117, a single working channel 290 is shown engagedwith the SI joint. In this example, the single working channel 290 canbe individually orientated and engaged with the SI joint, and separatelyas second working channel 290 may be engaged with the preferredinsertion point on the ilium, as shown in FIG. 118. This embodimentprovides the flexibility of individually orienting the two workingchannels. Subsequently, an adjustable rack 161 may be engaged with boththe of the individual working channels 290 as shown in FIG. 119, therebystabilizing the two working channels and maintaining their orientationrelative to one another. It is to be appreciated that the two workingchannels in this example may be stabilized by other or additionalmethods.

In some embodiments, the working channel may have two barrel or morebarrels (e.g., 3, 4, or more barrels, in various orientations—parallel,skewed, etc.), each capable of receiving surgical implements and beingused to introduce implants or other devices or materials into the SIjoint. For instance, the two or more barrels may include two parallelbarrels, two skewed barrels, three parallel barrels in a single plane,three parallel barrels in a triangular arrangement, etc. As an example,and without limiting the invention, FIG. 120 shows an individual workingchannel 295 engaged with the SI joint having two parallel barrels. Theadditional barrel may facilitate the formation of a second void and theinsertion of a second fusion implant or some other fusion device or bonegraft material in the second void. As an example, and withoutlimitation, FIG. 121 shows a posterior view of the SI joint having twofusion implants 151 inserted therein. An exposure device having twoparallel barrels such as working channel 295 may be used to insert twofusion implants into the SI joint, as shown in FIG. 121.

The working channel 295 may be used individually in a SI joint fusionprocedure, or in combination with another working channel. For example,and without limiting the invention, FIG. 122 shows an exemplary workingchannel 290 that may be used in conjunction with the working channel295, allowing for insertion of a joint fixation device in the ilium andsacrum. The working channels 290 and 295 may also be connected to oneanother by an adjustable rack, as described above, thereby stabilizingthe two working channels and maintaining their orientation relative toone another. It is to be appreciated that working channels having two ormore barrels may fixedly attached to a second working channel at anangle by a connecting member, as described in the examples above. As anexample, and without limitation, FIGS. 123-124 show posterior andsuperior views of an SI joint having two fusion implants 151 insertedtherein, and a fixation device 157 implanted in the iliac wing 100 andthe body of S1 of the sacrum 101. The fusion implants 151 sit in the SIjoint 102 between the articular surfaces of the sacrum 101 and the iliacwing 100. The fixation device 157 passes through the iliac wing 100 andinto the body of S1 of the sacrum 101 without traversing (passingthrough) the SI joint 102. An exposure device having two parallelbarrels such as working channel 295 may be used to insert two fusionimplants into the SI joint, and a second working channel may be used toinsert the joint fixation device in the iliac wing and the sacrum, asshown in FIGS. 123-124.

It is also to be appreciated that the individual working channel havingtwo or more barrels are not limited to SI joint fusion procedures, andmay have other beneficial applications. Furthermore, the other workingchannel apparatuses may be useful in other procedures as well. Forinstance, the working channels of the present invention may beassociated with various racks (e.g., having varying lengths and means ofattachment) that facilitate procedures where two difficult surgicalsites are needed.

It is to be further appreciated that the working channel apparatuses(exposure devices) described herein can be utilized in SI joint fusionprocedures on both SI joints of a patient simultaneously. As shown inFIG. 125, the presently described exposure devices can be utilized in abilateral SI joint procedure.

The methods described herein may be used to treat both of the patient'sSI joints either at the same or approximately the same time (e.g.,during the same procedure) or in sequence.

It is to be understood that variations and modifications of the presentinvention may be made without departing from the scope thereof. It isalso to be understood that the present invention is not to be limited bythe specific embodiments disclosed herein, but only in accordance withthe appended claims when read in light of the foregoing specification.

What is claimed:
 1. A method for repairing a sacroiliac joint of apatient, comprising: a. creating a first incision proximal to thepatient's sacroiliac joint; b. inserting a working channel into saidfirst incision, said working channel having a hollow barrel with aninterior guidance slot in an interior diameter of the hollow barrel thatdoes not traverse an outer diameter of said hollow barrel forcontrolling the advancement of surgical tools passed through saidworking channel, and having at least one tang on a distal end thereof;c. creating a void in said sacroiliac joint; and d. inserting a fusionimplant into said void, wherein said fusion implant includes at leastone protrusion that engages with bone tissue in an articular surface ofat least one of the sacrum and the ilium of said sacroiliac jointthereby preventing pullout of the fusion implant.
 2. The method of claim1, wherein said fusion implant has a central body and said at least oneprotrusion that extends from said central body and fixes relativepositions of said ilium and sacrum with engagement of said at least oneprotrusion with said ilium and sacrum.
 3. The method of claim 2, whereinsaid at least one protrusion includes an anchor that penetrates at leastone of the patient's ilium and the patient's sacrum and thereby fixesrelative positions of said ilium and sacrum.
 4. The method of claim 3,wherein said anchor is a helical anchor operable to substantially fixthe patient's ilium to the patient's sacrum, thereby substantiallyimmobilizing the patient's sacroiliac joint.
 5. The method of claim 2,wherein said fusion implant comprises a cavity for holding afusion-promoting material and having at least one hole therein forallowing the growth of bone tissue into said cavity.
 6. The method ofclaim 1, wherein the inserting said fusion implant comprises: a.attaching said fusion implant to an inserter having a plurality ofimplant engagement arms at a distal end of said inserter by engagingsaid implant engagement arms with slots on a proximal end of said fusionimplant, said inserter further having a slot-engagement protrusion forengaging with said interior guidance slot; and b. inserting saidinserter into the hollow barrel of said working channel with saidslot-engagement protrusion aligned with said interior guidance slotwithin the interior diameter of said hollow barrel and advancing saidinserter until said interior guidance slot arrests the penetration ofsaid inserter and said fusion implant into said sacroiliac joint at apre-determined depth.
 7. The method of claim 1, wherein the step ofcreating the void in said sacroiliac joint comprises inserting a rasphaving a slot-engagement protrusion into the hollow barrel of saidworking channel with said slot-engagement protrusion nested in theinterior guidance slot in the interior diameter of said hollow barrel,wherein engagement of said slot-engagement protrusion with said interiorguidance slot controls the depth of advancement of said rasp throughsaid hollow barrel and maintains said rasp in proper orientation forinsertion in the void.
 8. The method of claim 1, wherein said interiorguidance slot is operable to engage and align a slot-engagementprotrusion of one or more surgical tools to be inserted into said hollowbarrel, wherein engagement of said slot-engagement protrusion with saidguidance slot controls the depth of advancement of surgical toolsthrough said hollow barrel and maintains said one or more surgical toolsin proper orientation for insertion into said incision.
 9. The method ofclaim 1, wherein the at least one tang comprises a plurality of blunttangs on the distal end thereof that are inserted between the articularsurfaces of an ilium and a sacrum of said sacroiliac joint to stabilizethe surgical channel tool as surgical instruments are passed through theworking channel into the sacroiliac joint.
 10. A method for repairing asacroiliac joint of a patient, comprising: a. creating a first incisionproximal to the patient's sacroiliac joint; b. inserting a surgicalchannel tool into said first incision from the posterior of the patient,said surgical channel tool having two bilateral blunt tangs on a distalend thereof that are inserted between the articular surfaces of an iliumand a sacrum of said sacroiliac joint to stabilize the surgical channeltool as surgical instruments are passed through a surgical channel ofsaid surgical channel tool and into the sacroiliac joint, said surgicalchannel including a hollow barrel having an interior guidance slot in aninterior diameter of said hollow barrel for controlling the depth ofadvancement of surgical tools into said surgical channel and maintainingsaid surgical tools in proper orientation for insertion into saidincision, wherein said interior guidance slot does not traverse an outerdiameter of said hollow barrel; c. creating a void in said sacroiliacjoint; d. inserting a fusion implant into said void through said hollowbarrel of said surgical channel tool using an inserter having aplurality of implant engagement arms at its distal end engaged withslots on a proximal end of said fusion implant, said fusion implanthaving at least one protrusion for engagement with bone tissue in anarticular surface of at least one of the sacrum and the ilium of saidsacroiliac joint; and e. driving said fusion implant into said void suchthat said at least one protrusion engages with said bone tissuepreventing pullout of the fusion implant, and said fusion implant fixesrelative positions of said sacrum and said ilium.
 11. The method ofclaim 10, wherein said at least one protrusion comprises a helicalanchor having a sharp end for piercing said bone tissue in an articularsurface of at least one of said sacrum and said ilium.
 12. The method ofclaim 10, wherein said fusion implant comprises a body having a cavitytherein and perforations on an exterior thereof that expose said cavityto an exterior of said body, and a hole in a proximal end of said bodyfor accessing an interior of said cavity.
 13. The method of claim 10,wherein said fusion implant is operable to connect said sacrum to saidilium in fixed relative positions in the sacroiliac joint.
 14. Themethod of claim 10, wherein the inserting the fusion implant comprises:a. inserting the inserter into said hollow barrel of said surgicalchannel tool, wherein said inserter has an insertion control protrusion;b. engaging said insertion control protrusion with the interior guidanceslot in the interior diameter of the hollow barrel for controlling theadvancement of said inserter into said surgical channel tool andpreventing rotation of said inserter; and c. advancing the inserteruntil said insertion control protrusion is arrested by the interiorguidance slot at a pre-determined point in the hollow barrel, and saidinserter is prevented from moving the fusion implant further into saidsacroiliac joint.
 15. The method of claim 10, wherein driving saidfusion implant into said void comprises pushing said fusion implant intosaid void such that the at least one protrusion contacts said bonetissue.
 16. The method of claim 10, wherein the step of creating thevoid in said sacroiliac joint comprises inserting a rasp having aslot-engagement protrusion into said hollow barrel of said surgicalchannel tool with said slot-engagement protrusion aligned with saidinterior guidance slot in the interior diameter of said hollow barrel,wherein engagement of said slot-engagement protrusion with said interiorguidance slot controls the depth of advancement of said rasp throughsaid hollow barrel and maintains said rasp in proper orientation forinsertion into said void.
 17. The method of claim 1, wherein saidinterior guidance slot in the interior diameter of said working channelis for alignment and engagement with a slot-engagement protrusion of oneor more surgical tools to be inserted into said hollow barrel, whereinengagement of said slot-engagement protrusion with said interiorguidance slot controls the advancement of surgical tools through saidhollow barrel and maintains said one or more surgical tools in properorientation for insertion into said incision.
 18. A method for repairinga sacroiliac joint of a patient, comprising: a. creating an incisionproximal to the patient's sacroiliac joint to allow access to theposterior portion of the sacroiliac joint; b. inserting a workingchannel of a surgical channel tool into said incision from the posteriorof the patient, said working channel having a plurality of blunt tangson a distal end thereof that are inserted between articular surfaces ofan ilium and a sacrum of said sacroiliac joint to stabilize the surgicalchannel tool as surgical instruments are passed through the workingchannel into the sacroiliac joint, said working channel including ahollow barrel having an interior guidance slot in an interior diameterof said hollow barrel for controlling a depth of advancement of surgicaltools into said working channel and maintaining said surgical tools inproper orientation for insertion into said incision, wherein saidinterior guidance slot does not traverse an outer diameter of saidhollow barrel; c. inserting a fusion implant having a plurality ofbone-engagement protrusions through said hollow barrel into saidsacroiliac joint using an inserter having a plurality of implantengagement arms at its distal end engaged with slots on a proximal endof said fusion implant, wherein said fusion implant is inserted on apath that is substantially parallel to articular surfaces of thesacroiliac joint, said inserter having an insertion control protrusionfor engagement with said interior guidance slot; d. advancing theinserter until said insertion control protrusion is arrested by saidinterior guidance slot in the hollow barrel and placing said fusionimplant into said sacroiliac joint, wherein said inserter is preventedfrom moving the fusion implant beyond a pre-determined point in saidsacroiliac joint; and e. driving said fusion implant into saidsacroiliac joint such that said plurality of bone-engagement protrusionsengage with said articular surfaces of said ilium and said sacrumthereby preventing pullout of the fusion implant from said sacroiliacjoint.
 19. The method of claim 18, wherein said engagement of saidfusion implant with said bone tissue fixes the relative position of saidsacrum and the ilium of said sacroiliac joint.
 20. The method of claim18, wherein said plurality of bone-engagement protrusions comprise ahelical anchor having a sharp end for piercing said bone tissue, andsaid helical anchor first penetrates said articular surface of said atleast one of said sacrum and said ilium.
 21. The method of claim 18,wherein no further fusion implants are introduced into said sacroiliacjoint and said fusion implant is sufficient to fuse the sacroiliacjoint.
 22. The method of claim 18, further comprising creating a void inthe sacroiliac joint having a complementary shape to said fusionimplant, wherein said fusion implant is inserted into said void.
 23. Themethod of claim 18, wherein engagement of said insertion controlprotrusion with said interior guidance slot maintains said inserter tooland said fusion implant in proper orientation for insertion of thefusion implant into said sacroiliac joint.